/*
 * Copyright (c) 1988-1989 Hans-J. Boehm, Alan J. Demers
 * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
 * Copyright (c) 1996-1999 by Silicon Graphics.  All rights reserved.
 * Copyright (c) 1999 by Hewlett-Packard Company.  All rights reserved.
 * Copyright (c) 2007 Free Software Foundation, Inc.
 * Copyright (c) 2000-2011 by Hewlett-Packard Development Company.
 * Copyright (c) 2009-2022 Ivan Maidanski
 *
 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 *
 * Permission is hereby granted to use or copy this program
 * for any purpose, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 */

/*
 * Note that this defines a large number of tuning hooks, which can
 * safely be ignored in nearly all cases.  For normal use it suffices
 * to call only GC_MALLOC and perhaps GC_REALLOC.
 * For better performance, also look at GC_MALLOC_ATOMIC, and
 * GC_enable_incremental.  If you need an action to be performed
 * immediately before an object is collected, look at GC_register_finalizer.
 * Everything else is best ignored unless you encounter performance
 * problems.
 */

#ifndef GC_H
#define GC_H

/* Help debug mixed up preprocessor symbols.    */
#if defined(WIN64) && !defined(_WIN64) && defined(_MSC_VER)
#  pragma message("Warning: Expecting _WIN64 for x64 targets!")
#endif

/* Define version numbers here to allow test on build machine   */
/* for cross-builds.  Note that this defines the header         */
/* version number, which may or may not match that of the       */
/* dynamic library.  GC_get_version() can be used to obtain     */
/* the latter.                                                  */
#include "gc_version.h"

#include "gc_config_macros.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef void *GC_PTR; /* preserved only for backward compatibility    */

/* Define word and signed word to be unsigned and signed types of the   */
/* size as char* or void*.                                              */
typedef GC_UNSIGNEDWORD GC_word;
typedef GC_SIGNEDWORD GC_signed_word;
#undef GC_SIGNEDWORD
#undef GC_UNSIGNEDWORD

#if (defined(_UINTPTR_T) || defined(_UINTPTR_T_DECLARED) \
     || defined(_UINTPTR_T_DEFINED))                     \
    && !defined(__MSYS__)
/* Note: MSYS2 might provide __uintptr_t but not uintptr_t. */
typedef uintptr_t GC_uintptr_t;
#else
typedef GC_word GC_uintptr_t;
#endif

/* Is first pointer has a smaller address than the second one?  The     */
/* arguments should be of the same pointer type, e.g. of char* type.    */
/* Ancient compilers might treat a pointer as a signed value, thus we   */
/* need a cast to unsigned word of each compared pointer.               */
#if defined(__GNUC__) && !defined(__CHERI_PURE_CAPABILITY__)
#  define GC_ADDR_LT(p, q) ((p) < (q))
#else
#  define GC_ADDR_LT(p, q) \
    ((GC_word)(GC_uintptr_t)(p) < (GC_word)(GC_uintptr_t)(q))
#endif

/* Get the GC library version. The returned value is a constant in the  */
/* form: ((version_major<<16) | (version_minor<<8) | version_micro).    */
GC_API GC_VERSION_VAL_T GC_CALL GC_get_version(void);

/* Public read-only variables.  The supplied getter functions are       */
/* preferred for new client code.                                       */

/* Counter incremented once per collection.  Includes empty collections */
/* at startup.  GC_get_gc_no() is unsynchronized, so it requires        */
/* GC_call_with_reader_lock() to avoid data race on multiprocessors.    */
GC_API GC_ATTR_DEPRECATED GC_word GC_gc_no;
GC_API GC_word GC_CALL GC_get_gc_no(void);

#ifdef GC_THREADS
/* GC is parallelized for performance on multiprocessors.  Set to     */
/* a non-zero value when client calls GC_start_mark_threads()         */
/* directly or starts the first non-main thread, provided the         */
/* collector is built with PARALLEL_MARK defined, and either          */
/* GC_MARKERS (or GC_NPROCS) environment variable is set to a value   */
/* bigger than 1, or multiple cores (processors) are available, or    */
/* the client calls GC_set_markers_count() before the collector       */
/* initialization.  After setting, GC_parallel value is equal to the  */
/* number of marker threads minus one (i.e. the number of existing    */
/* parallel marker threads excluding the initiating one).             */
GC_API GC_ATTR_DEPRECATED int GC_parallel;
#endif

/* Return value of GC_parallel.  Does not acquire the allocator lock.   */
GC_API int GC_CALL GC_get_parallel(void);

/* Set the number of marker threads (including the initiating one)      */
/* to the desired value at start-up.  Zero value means the collector    */
/* is to decide.  If the correct non-zero value is passed, then later   */
/* GC_parallel will be set to the value minus one.  Has no effect if    */
/* called after the collector initialization.  Does not itself cause    */
/* creation of the marker threads.  Does not use any synchronization.   */
GC_API void GC_CALL GC_set_markers_count(unsigned);

/* Public R/W variables.  The supplied setter and getter functions are  */
/* preferred for new client code.                                       */

/* When there is insufficient memory to satisfy an allocation request,  */
/* we return (*GC_oom_fn)(size).  If it returns, it must return either  */
/* NULL or a valid pointer to a previously allocated heap object.       */
/* By default, this just returns NULL.  GC_oom_fn must not be 0.  Both  */
/* the setter and the getter acquire the allocator lock (in the reader  */
/* mode in case of the getter) to avoid data race.                      */
typedef void *(GC_CALLBACK *GC_oom_func)(size_t /* bytes_requested */);
GC_API GC_ATTR_DEPRECATED GC_oom_func GC_oom_fn;
GC_API void GC_CALL GC_set_oom_fn(GC_oom_func) GC_ATTR_NONNULL(1);
GC_API GC_oom_func GC_CALL GC_get_oom_fn(void);

/* Invoked when the heap grows or shrinks.  Called with the world       */
/* stopped (and the allocator lock held).  May be 0.  Both the setter   */
/* and the getter acquire the allocator lock (in the reader mode in     */
/* case of the getter).                                                 */
typedef void(GC_CALLBACK *GC_on_heap_resize_proc)(GC_word /* new_size */);
GC_API GC_ATTR_DEPRECATED GC_on_heap_resize_proc GC_on_heap_resize;
GC_API void GC_CALL GC_set_on_heap_resize(GC_on_heap_resize_proc);
GC_API GC_on_heap_resize_proc GC_CALL GC_get_on_heap_resize(void);

typedef enum {
  GC_EVENT_START /* COLLECTION */,
  GC_EVENT_MARK_START,
  GC_EVENT_MARK_END,
  GC_EVENT_RECLAIM_START,
  GC_EVENT_RECLAIM_END,
  GC_EVENT_END /* COLLECTION */,
  GC_EVENT_PRE_STOP_WORLD /* STOPWORLD_BEGIN */,
  GC_EVENT_POST_STOP_WORLD /* STOPWORLD_END */,
  GC_EVENT_PRE_START_WORLD /* STARTWORLD_BEGIN */,
  GC_EVENT_POST_START_WORLD /* STARTWORLD_END */,
  GC_EVENT_THREAD_SUSPENDED,
  GC_EVENT_THREAD_UNSUSPENDED
} GC_EventType;

/* Invoked to indicate progress through the collection process.         */
/* Not used for thread suspend/resume notifications.  Called with the   */
/* allocator lock held (or, even, the world stopped).  May be 0 (means  */
/* no notifier).  Both the setter and the getter acquire the allocator  */
/* lock (in the reader mode in case of the getter).                     */
typedef void(GC_CALLBACK *GC_on_collection_event_proc)(GC_EventType);
GC_API void GC_CALL GC_set_on_collection_event(GC_on_collection_event_proc);
GC_API GC_on_collection_event_proc GC_CALL GC_get_on_collection_event(void);

#if defined(GC_THREADS) || (defined(GC_BUILD) && defined(NN_PLATFORM_CTR))
/* Invoked when a thread is suspended or resumed during collection.   */
/* Called with the allocator lock held (and the world stopped         */
/* partially).  May be 0 (means no notifier).  Both the setter and    */
/* the getter acquire the allocator lock (in the reader mode in case  */
/* of the getter).                                                    */
typedef void(GC_CALLBACK *GC_on_thread_event_proc)(GC_EventType,
                                                   void * /* thread_id */);
GC_API void GC_CALL GC_set_on_thread_event(GC_on_thread_event_proc);
GC_API GC_on_thread_event_proc GC_CALL GC_get_on_thread_event(void);
#endif

/* Turn on the leak-finding mode (do not actually garbage collect, but  */
/* simply report inaccessible memory that was not deallocated with      */
/* GC_FREE).  Initial value is determined by FIND_LEAK macro.           */
/* The value should not typically be modified after the collector       */
/* initialization (and, thus, it does not use or need synchronization). */
GC_API GC_ATTR_DEPRECATED int GC_find_leak;
GC_API void GC_CALL GC_set_find_leak(int);
GC_API int GC_CALL GC_get_find_leak(void);

/* Arrange for pointers to object interiors to be recognized as valid.  */
/* Typically should not be changed after the collector initialization   */
/* (in case of calling it after the collector is initialized, the       */
/* setter acquires the allocator lock).  Must be only 0 or 1.           */
/* The initial value depends on whether the GC is built with            */
/* ALL_INTERIOR_POINTERS macro defined or not.  This also affects,      */
/* unless GC_get_dont_add_byte_at_end() returns a non-zero value,       */
/* whether the object sizes are increased by at least a byte to allow   */
/* "off the end" pointer recognition (but the size is not increased     */
/* for uncollectible objects as well as for ignore-off-page objects of  */
/* at least heap block size).                                           */
GC_API GC_ATTR_DEPRECATED int GC_all_interior_pointers;
GC_API void GC_CALL GC_set_all_interior_pointers(int);
GC_API int GC_CALL GC_get_all_interior_pointers(void);

/* If nonzero, finalizers will only be run in response to an explicit   */
/* GC_invoke_finalizers call.  The default is determined by whether the */
/* FINALIZE_ON_DEMAND macro is defined when the collector is built.     */
/* The setter and the getter are unsynchronized.                        */
GC_API GC_ATTR_DEPRECATED int GC_finalize_on_demand;
GC_API void GC_CALL GC_set_finalize_on_demand(int);
GC_API int GC_CALL GC_get_finalize_on_demand(void);

/* Mark objects reachable from finalizable objects in a separate        */
/* post-pass.  This makes it a bit safer to use                         */
/* non-topologically-ordered finalization.  Default value is determined */
/* by JAVA_FINALIZATION macro.  Enables                                 */
/* GC_register_finalizer_unreachable to work correctly.  The setter and */
/* the getter are unsynchronized.                                       */
GC_API GC_ATTR_DEPRECATED int GC_java_finalization;
GC_API void GC_CALL GC_set_java_finalization(int);
GC_API int GC_CALL GC_get_java_finalization(void);

/* Invoked by the collector when there are objects to be finalized.     */
/* Invoked at most once per collection cycle.  Never invoked unless     */
/* GC_finalize_on_demand is set.  Typically this will notify            */
/* a finalization thread, which will call GC_invoke_finalizers in       */
/* response.  May be 0 (means no notifier).  Both the setter and the    */
/* getter acquire the allocator lock (in the reader mode in case of the */
/* getter).                                                             */
typedef void(GC_CALLBACK *GC_finalizer_notifier_proc)(void);
GC_API GC_ATTR_DEPRECATED GC_finalizer_notifier_proc GC_finalizer_notifier;
GC_API void GC_CALL GC_set_finalizer_notifier(GC_finalizer_notifier_proc);
GC_API GC_finalizer_notifier_proc GC_CALL GC_get_finalizer_notifier(void);

/* The functions called to report pointer checking errors.  Called      */
/* without the allocator lock held.  The default behavior is to fail    */
/* with the appropriate message which includes the pointers.  The       */
/* functions (variables) must not be 0.  Both the setters and the       */
/* getters are unsynchronized.                                          */
typedef void(GC_CALLBACK *GC_valid_ptr_print_proc_t)(void *);
typedef void(GC_CALLBACK *GC_same_obj_print_proc_t)(void * /* p */,
                                                    void * /* q */);
GC_API GC_ATTR_DEPRECATED GC_same_obj_print_proc_t GC_same_obj_print_proc;
GC_API GC_ATTR_DEPRECATED GC_valid_ptr_print_proc_t
    GC_is_valid_displacement_print_proc;
GC_API GC_ATTR_DEPRECATED GC_valid_ptr_print_proc_t GC_is_visible_print_proc;
GC_API void GC_CALL GC_set_same_obj_print_proc(GC_same_obj_print_proc_t)
    GC_ATTR_NONNULL(1);
GC_API GC_same_obj_print_proc_t GC_CALL GC_get_same_obj_print_proc(void);
GC_API void
    GC_CALL GC_set_is_valid_displacement_print_proc(GC_valid_ptr_print_proc_t)
        GC_ATTR_NONNULL(1);
GC_API GC_valid_ptr_print_proc_t GC_CALL
GC_get_is_valid_displacement_print_proc(void);
GC_API void GC_CALL GC_set_is_visible_print_proc(GC_valid_ptr_print_proc_t)
    GC_ATTR_NONNULL(1);
GC_API GC_valid_ptr_print_proc_t GC_CALL GC_get_is_visible_print_proc(void);

/* A flag indicating "do not collect" mode.  This overrides explicit    */
/* GC_gcollect() calls as well.  Used as a counter, so that nested      */
/* enabling and disabling work correctly.  Should normally be updated   */
/* with GC_enable() and GC_disable() calls.  Direct assignment to       */
/* GC_dont_gc is deprecated.  To check whether collections are          */
/* disabled, GC_is_disabled() is preferred for new code.                */
GC_API
#ifndef GC_DONT_GC
GC_ATTR_DEPRECATED
#endif
int GC_dont_gc;

/* Do not expand the heap unless explicitly requested or forced to.     */
/* The setter and the getter are unsynchronized.                        */
GC_API GC_ATTR_DEPRECATED int GC_dont_expand;
GC_API void GC_CALL GC_set_dont_expand(int);
GC_API int GC_CALL GC_get_dont_expand(void);

/* Causes the non-incremental collector to use the entire heap before   */
/* collecting.  This sometimes results in more large block              */
/* fragmentation, since very large blocks will tend to get broken up    */
/* during each collection cycle.  It is likely to result in a larger    */
/* working set, but lower collection frequencies, and hence fewer       */
/* instructions executed in the collector.                              */
GC_API GC_ATTR_DEPRECATED int GC_use_entire_heap;

/* Number of partial collections between full collections.  Matters     */
/* only if GC_is_incremental_mode().  Full collections are also         */
/* triggered if the collector detects a substantial increase in the     */
/* number of the in-use heap blocks.  Values in the tens are now        */
/* perfectly reasonable, unlike for earlier GC versions.  The setter    */
/* and the getter are unsynchronized, so GC_call_with_alloc_lock()      */
/* (GC_call_with_reader_lock() in case of the getter) is required to    */
/* avoid data race (if the value is modified after the collector is put */
/* into the multi-threaded mode).                                       */
GC_API GC_ATTR_DEPRECATED int GC_full_freq;
GC_API void GC_CALL GC_set_full_freq(int);
GC_API int GC_CALL GC_get_full_freq(void);

/* Bytes not considered candidates for collection.  Used only to        */
/* control scheduling of collections.  Updated by                       */
/* GC_malloc_uncollectable() and GC_free().  Wizards only.  The setter  */
/* and the getter are unsynchronized, so GC_call_with_alloc_lock()      */
/* (GC_call_with_reader_lock() in case of the getter) is required to    */
/* avoid data race (if the value is modified after the collector is put */
/* into the multi-threaded mode).                                       */
GC_API GC_ATTR_DEPRECATED GC_word GC_non_gc_bytes;
GC_API void GC_CALL GC_set_non_gc_bytes(GC_word);
GC_API GC_word GC_CALL GC_get_non_gc_bytes(void);

/* Do not register dynamic library data segments automatically.  Also,  */
/* if set by the collector itself (during a collection), this means     */
/* that such a registration is not supported.  Wizards only.  Should    */
/* be set only if the client explicitly registers all roots.  (In some  */
/* environments like Microsoft Windows and Apple's Darwin, this may     */
/* also prevent registration of the main data segment as a part of the  */
/* root set.)  The setter and the getter are unsynchronized.            */
GC_API GC_ATTR_DEPRECATED int GC_no_dls;
GC_API void GC_CALL GC_set_no_dls(int);
GC_API int GC_CALL GC_get_no_dls(void);

/* We try to make sure that we allocate at least                        */
/* N/GC_free_space_divisor bytes between collections, where N is twice  */
/* the number of traced bytes, plus the number of untraced bytes (i.e.  */
/* bytes in the "atomic" objects), plus a rough estimate of the root    */
/* set size.  N approximates GC tracing work per collection.  The       */
/* initial value is GC_FREE_SPACE_DIVISOR.  Increasing its value will   */
/* use less space but more collection time.  Decreasing it will         */
/* appreciably decrease collection time at the expense of space.        */
/* The setter and the getter are unsynchronized, so                     */
/* GC_call_with_alloc_lock() (GC_call_with_reader_lock() in case of the */
/* getter) is required to avoid data race (if the value is modified     */
/* after the collector is put into the multi-threaded mode).            */
/* In GC v7.1 and before, the setter returned the old value.            */
GC_API GC_ATTR_DEPRECATED GC_word GC_free_space_divisor;
GC_API void GC_CALL GC_set_free_space_divisor(GC_word);
GC_API GC_word GC_CALL GC_get_free_space_divisor(void);

/* The maximum number of collections attempted before reporting out of  */
/* memory after heap expansion fails.  Initially 0.  The setter and     */
/* getter are unsynchronized, so GC_call_with_alloc_lock()              */
/* (GC_call_with_reader_lock() in case of the getter) is required to    */
/* avoid data race (if the value is modified after the collector is put */
/* into the multi-threaded mode).                                       */
GC_API GC_ATTR_DEPRECATED GC_word GC_max_retries;
GC_API void GC_CALL GC_set_max_retries(GC_word);
GC_API GC_word GC_CALL GC_get_max_retries(void);

/* The cold end (bottom) of user stack.  May be set in the client prior */
/* to calling any GC_ routines.  This avoids some overhead, and         */
/* potentially some signals that can confuse debuggers.  Otherwise the  */
/* collector attempts to set it automatically.  For multi-threaded      */
/* code, this is the cold end of the stack for the primordial thread.   */
/* For multi-threaded code, altering GC_stackbottom value directly      */
/* after the collector initialization has no effect.  Portable clients  */
/* should use GC_set_stackbottom(), GC_get_stack_base(),                */
/* GC_call_with_gc_active() and GC_register_my_thread() instead.        */
GC_API GC_ATTR_DEPRECATED char *GC_stackbottom;

/* Do not collect as part of the collector initialization.  Should be   */
/* set only if the client wants a chance to manually initialize the     */
/* root set before the first collection.  Interferes with blacklisting. */
/* Wizards only.  The setter and the getter are unsynchronized (and no  */
/* external locking is needed since the value is accessed at the the    */
/* collector initialization only).                                      */
GC_API GC_ATTR_DEPRECATED int GC_dont_precollect;
GC_API void GC_CALL GC_set_dont_precollect(int);
GC_API int GC_CALL GC_get_dont_precollect(void);

/* If incremental collection is enabled, we try to terminate            */
/* collections after this many milliseconds (plus the amount of         */
/* nanoseconds as given in the latest GC_set_time_limit_tv call, if     */
/* any).  Not a hard time bound.  Setting this variable to              */
/* GC_TIME_UNLIMITED essentially disables incremental collection (i.e.  */
/* disables the "pause time exceeded" tests) while leaving generational */
/* collection enabled.  The setter and the getter are unsynchronized,   */
/* so GC_call_with_alloc_lock() (GC_call_with_reader_lock() in case of  */
/* the getter) is required to avoid data race (if the value is modified */
/* after the collector is put into the multi-threaded mode).  The       */
/* setter does not update the value of the nanosecond part of the time  */
/* limit (it is zero unless ever set by GC_set_time_limit_tv call).     */
GC_API GC_ATTR_DEPRECATED unsigned long GC_time_limit;
#define GC_TIME_UNLIMITED 999999
GC_API void GC_CALL GC_set_time_limit(unsigned long);
GC_API unsigned long GC_CALL GC_get_time_limit(void);

/* A portable type definition of time with a nanosecond precision.      */
struct GC_timeval_s {
  unsigned long tv_ms;   /* time in milliseconds */
  unsigned long tv_nsec; /* nanoseconds fraction (<1000000) */
};

/* Public procedures */

/* Set/get the time limit of the incremental collections.  This is      */
/* similar to GC_set_time_limit and GC_get_time_limit but the time is   */
/* provided with the nanosecond precision.  The value of tv_nsec part   */
/* should be less than a million.  If the value of tv_ms part is        */
/* GC_TIME_UNLIMITED then tv_nsec is ignored.  Initially, the value of  */
/* tv_nsec part of the time limit is zero.  The functions do not use    */
/* any synchronization.  Defined only if the library has been compiled  */
/* without NO_CLOCK.                                                    */
GC_API void GC_CALL GC_set_time_limit_tv(struct GC_timeval_s);
GC_API struct GC_timeval_s GC_CALL GC_get_time_limit_tv(void);

/* Set/get the minimum value of the ratio of allocated bytes since      */
/* garbage collection to the amount of finalizers created since that    */
/* collection (value > GC_bytes_allocd/(GC_fo_entries-last_fo_entries)) */
/* which triggers the collection instead heap expansion.  The value     */
/* has no effect in the GC incremental mode.  The default value is      */
/* 10000 unless GC_ALLOCD_BYTES_PER_FINALIZER macro with a custom value */
/* is defined to build the GC.  The default value might be not the      */
/* right choice for clients where e.g. most objects have a finalizer.   */
/* Zero value effectively disables taking amount of finalizers in the   */
/* decision whether to collect or not.  The functions do not use any    */
/* synchronization.                                                     */
GC_API void GC_CALL GC_set_allocd_bytes_per_finalizer(GC_word);
GC_API GC_word GC_CALL GC_get_allocd_bytes_per_finalizer(void);

/* Tell the collector to start various performance measurements.        */
/* Only the total time taken by full collections and the average time   */
/* spent in the world-stopped collections are calculated, as of now.    */
/* And, currently, there is no way to stop the measurements.            */
/* The function does not use any synchronization.  Defined only if the  */
/* library has been compiled without NO_CLOCK.                          */
GC_API void GC_CALL GC_start_performance_measurement(void);

/* Get the total time of all full collections since the start of the    */
/* performance measurements.  Includes time spent in the supplementary  */
/* actions like blacklists promotion, marks clearing, free lists        */
/* reconstruction and objects finalization.  The measurement unit is a  */
/* millisecond.  Note that the returned value wraps around on overflow. */
/* The function does not use any synchronization.  Defined only if the  */
/* library has been compiled without NO_CLOCK.                          */
GC_API unsigned long GC_CALL GC_get_full_gc_total_time(void);

/* Same as GC_get_full_gc_total_time but takes into account all mark    */
/* phases with the world stopped and nothing else.                      */
GC_API unsigned long GC_CALL GC_get_stopped_mark_total_time(void);

/* Get the average time spent in all mark phases with the world         */
/* stopped.  The average value is computed since the start of the       */
/* performance measurements (or right since the collector               */
/* initialization if the GC logging is enabled).  The result is in      */
/* nanoseconds.  The function acquires the allocator lock (in the       */
/* reader mode) to avoid data race.  Defined only if the library has    */
/* been compiled without NO_CLOCK.                                      */
GC_API unsigned long GC_CALL GC_get_avg_stopped_mark_time_ns(void);

/* Set whether the garbage collector will allocate executable memory    */
/* pages or not.  A non-zero argument instructs the collector to        */
/* allocate memory with the executable flag on.  Must be called before  */
/* the collector is initialized.  May have no effect on some platforms. */
/* The default value is controlled by NO_EXECUTE_PERMISSION macro (if   */
/* present then the flag is off).  Portable clients should have         */
/* GC_set_pages_executable(1) call (before GC_INIT) provided they are   */
/* going to execute code on any of the GC-allocated memory objects.     */
GC_API void GC_CALL GC_set_pages_executable(int);

/* Returns non-zero value if the garbage collector is set to the        */
/* allocate-executable-memory mode.  The mode could be changed by       */
/* GC_set_pages_executable (before GC_INIT) unless the former has no    */
/* effect on the platform.  Does not use or need synchronization.       */
GC_API int GC_CALL GC_get_pages_executable(void);

/* The setter and the getter of the minimum value returned by the       */
/* internal min_bytes_allocd().  The value should not be zero; the      */
/* default value is one.  Not synchronized.                             */
GC_API void GC_CALL GC_set_min_bytes_allocd(size_t);
GC_API size_t GC_CALL GC_get_min_bytes_allocd(void);

/* Set/get the size in pages of units operated by GC_collect_a_little.  */
/* The value should not be zero.  Not synchronized.                     */
GC_API void GC_CALL GC_set_rate(int);
GC_API int GC_CALL GC_get_rate(void);

/* Set/get the maximum number of prior attempts at the world-stop       */
/* marking.  Not synchronized.                                          */
GC_API void GC_CALL GC_set_max_prior_attempts(int);
GC_API int GC_CALL GC_get_max_prior_attempts(void);

/* Control whether to disable algorithm deciding if a collection should */
/* be started when we allocated enough to amortize the collection.      */
/* Both the setter and the getter acquire the allocator lock (in the    */
/* reader mode in case of the getter) to avoid data race.               */
GC_API void GC_CALL GC_set_disable_automatic_collection(int);
GC_API int GC_CALL GC_get_disable_automatic_collection(void);

/* Overrides the default handle-fork mode.  Non-zero value means GC     */
/* should install proper pthread_atfork handlers.  Has effect only if   */
/* called before GC_INIT.  Clients should invoke GC_set_handle_fork     */
/* with non-zero argument if going to use fork with GC functions called */
/* in the forked child.  (Note that such client and atfork handlers     */
/* activities are not fully POSIX-compliant.)  GC_set_handle_fork       */
/* instructs GC_init to setup GC fork handlers using pthread_atfork,    */
/* the latter might fail (or, even, absent on some targets) causing     */
/* abort at the collector initialization.  Issues with missing (or      */
/* failed) pthread_atfork() could be avoided by invocation of           */
/* GC_set_handle_fork(-1) at application start-up and surrounding each  */
/* fork() with the relevant GC_atfork_prepare/parent/child calls.       */
GC_API void GC_CALL GC_set_handle_fork(int);

/* Routines to handle POSIX fork() manually (no-op if handled           */
/* automatically).  GC_atfork_prepare should be called immediately      */
/* before fork(); GC_atfork_parent should be invoked just after fork in */
/* the branch that corresponds to parent process (i.e., fork result is  */
/* non-zero); GC_atfork_child is to be called immediately in the child  */
/* branch (i.e., fork result is 0).  Note that GC_atfork_child() call   */
/* should, of course, precede GC_start_mark_threads call (if any).      */
GC_API void GC_CALL GC_atfork_prepare(void);
GC_API void GC_CALL GC_atfork_parent(void);
GC_API void GC_CALL GC_atfork_child(void);

/* Initialize the collector.  Portable clients should call GC_INIT()    */
/* from the main program instead.                                       */
GC_API void GC_CALL GC_init(void);

/* Return 1 (true) if the collector is initialized (or, at least, the   */
/* initialization is in progress), 0 otherwise.                         */
GC_API int GC_CALL GC_is_init_called(void);

/* Perform the collector shutdown.  (E.g. dispose critical sections on  */
/* Win32 target.)  A duplicate invocation is a no-op.  GC_INIT should   */
/* not be called after the shutdown.  See also GC_win32_free_heap().    */
GC_API void GC_CALL GC_deinit(void);

/* General purpose allocation routines, with roughly malloc calling     */
/* conv.  The atomic versions promise that no relevant pointers are     */
/* contained in the object.  The non-atomic versions guarantee that the */
/* new object is cleared.  GC_malloc_uncollectable allocates            */
/* an object that is scanned for pointers to collectible                */
/* objects, but is not itself collectible.  The object is scanned even  */
/* if it does not appear to be reachable.  GC_malloc_uncollectable and  */
/* GC_free called on the resulting object implicitly update             */
/* GC_non_gc_bytes appropriately.                                       */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_malloc(size_t /* size_in_bytes */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_malloc_atomic(size_t /* size_in_bytes */);
GC_API GC_ATTR_MALLOC char *GC_CALL GC_strdup(const char *);
GC_API GC_ATTR_MALLOC char *GC_CALL GC_strndup(const char *, size_t)
    GC_ATTR_NONNULL(1);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_malloc_uncollectable(size_t /* size_in_bytes */);
GC_API GC_ATTR_DEPRECATED void *GC_CALL GC_malloc_stubborn(size_t);

/* The routines that guarantee the requested alignment of the allocated */
/* memory object.  The align argument should be non-zero and a power    */
/* of two; GC_posix_memalign() also requires it to be not less than     */
/* size of a pointer.  Note that posix_memalign() does not change value */
/* of (*memptr) in case of failure (i.e. when the result is non-zero).  */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(2) void *GC_CALL
    GC_memalign(size_t /* align */, size_t /* lb */);
GC_API int GC_CALL GC_posix_memalign(void ** /* memptr */, size_t /* align */,
                                     size_t /* lb */) GC_ATTR_NONNULL(1);
#ifndef GC_NO_VALLOC
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_valloc(size_t /* lb */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_pvalloc(size_t /* lb */);
#endif /* !GC_NO_VALLOC */

/* Explicitly deallocate an object.  Dangerous if used incorrectly.     */
/* Requires a pointer to the base of an object.                         */
/* An object should not be enabled for finalization (and it should not  */
/* contain registered disappearing links of any kind) when it is        */
/* explicitly deallocated.                                              */
/* GC_free(0) is a no-op, as required by ANSI C for free.               */
GC_API void GC_CALL GC_free(void *);

/* A symbol to be intercepted by heap profilers so that they can        */
/* accurately track allocations.  Programs such as Valgrind massif      */
/* and KDE heaptrack do tracking of allocated objects by overriding     */
/* common allocator methods (e.g. malloc and free).  However, because   */
/* the collector does not work by calling standard allocation methods   */
/* on objects that were reclaimed, we need a way to tell the profiler   */
/* that an object has been freed.  This function is not intended to     */
/* be called by the client, it should be used for the interception      */
/* purpose only.  The collector calls this function internally whenever */
/* an object is freed.  Defined only if the library has been compiled   */
/* with VALGRIND_TRACKING.                                              */
GC_API void GC_CALLBACK GC_free_profiler_hook(void *);

/* The "stubborn" objects allocation is not supported anymore.  Exists  */
/* only for the backward compatibility.                                 */
#define GC_MALLOC_STUBBORN(sz) GC_MALLOC(sz)
#define GC_NEW_STUBBORN(t) GC_NEW(t)
#define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p)
GC_API GC_ATTR_DEPRECATED void GC_CALL GC_change_stubborn(const void *);

/* Inform the collector that the object has been changed.               */
/* Only non-NULL pointer stores into the object are considered to be    */
/* changes.  Matters only if the incremental collection is enabled in   */
/* the manual VDB mode (otherwise the function does nothing).           */
/* Should be followed typically by GC_reachable_here called for each    */
/* of the stored pointers.                                              */
GC_API void GC_CALL GC_end_stubborn_change(const void *) GC_ATTR_NONNULL(1);

/* Return a pointer to the base (lowest address) of an object given     */
/* a pointer to a location within the object.                           */
/* I.e., map an interior pointer to the corresponding base pointer.     */
/* Note that with debugging allocation, this returns a pointer to the   */
/* actual base of the object, i.e. the debug information, not to        */
/* the base of the user object.                                         */
/* Return 0 if displaced_pointer doesn't point to within a valid        */
/* object.                                                              */
/* Note that a deallocated object in the garbage collected heap         */
/* may be considered valid, even if it has been deallocated with        */
/* GC_free.                                                             */
GC_API void *GC_CALL GC_base(void * /* displaced_pointer */);

/* Return 1 (true) if the argument points to somewhere in the GC heap,  */
/* 0 otherwise.  Primary use is as a fast alternative to GC_base() to   */
/* check whether the given object is allocated by the collector or not. */
/* It is assumed that the collector is already initialized.             */
GC_API int GC_CALL GC_is_heap_ptr(const void *);

/* Given a pointer to the base of an object, return its size in bytes.  */
/* (For small objects this also happens to work from interior pointers, */
/* but that should not be relied upon.)  The returned size may be       */
/* slightly larger than what was originally requested.  The argument    */
/* may be NULL (causing 0 to be returned).                              */
GC_API size_t GC_CALL GC_size(const void * /* obj_addr */);

/* For compatibility with C library.  This is occasionally faster than  */
/* a malloc followed by a bcopy.  But if you rely on that, either here  */
/* or with the standard C library, your code is broken.  In my          */
/* opinion, it shouldn't have been invented, but now we're stuck. -HB   */
/* The resulting object has the same kind as the original.              */
/* It is an error to have changes enabled for the original object.      */
/* It does not change the content of the object from its beginning to   */
/* the minimum of old size and new_size_in_bytes; the content above in  */
/* case of object size growth is initialized to zero (not guaranteed    */
/* for atomic object type).  The function follows ANSI conventions for  */
/* NULL old_object (i.e., equivalent to GC_malloc regardless of new     */
/* size).  If new size is zero (and old_object is non-NULL) then the    */
/* call is equivalent to GC_free (and NULL is returned).  If old_object */
/* is non-NULL, it must have been returned by an earlier call to        */
/* GC_malloc* or GC_realloc.  In case of the allocation failure, the    */
/* memory pointed by old_object is untouched (and not freed).           */
/* If the returned pointer is not the same as old_object and both of    */
/* them are non-NULL then old_object is freed.  Returns either NULL (in */
/* case of the allocation failure or zero new size) or pointer to the   */
/* allocated memory.                                                    */
GC_API void *GC_CALL GC_realloc(void * /* old_object */,
                                size_t /* new_size_in_bytes */)
    /* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2);

/* Increase the heap size explicitly.  Performs the GC initialization   */
/* as well (if not yet).  Returns 0 on failure, 1 on success.           */
GC_API int GC_CALL GC_expand_hp(size_t /* number_of_bytes */);

/* Limit the heap size to n bytes.  Useful when you're debugging,       */
/* especially on systems that don't handle running out of memory well.  */
/* n == 0 ==> unbounded.  This is the default.  This setter function is */
/* unsynchronized (so it might require GC_call_with_alloc_lock to avoid */
/* data race).                                                          */
GC_API void GC_CALL GC_set_max_heap_size(GC_word /* n */);

/* Inform the collector that a certain section of statically allocated  */
/* memory contains no pointers to garbage collected memory.  Thus it    */
/* need not be scanned.  This is sometimes important if the application */
/* maps large read/write files into the address space, which could be   */
/* mistaken for dynamic library data segments on some systems.          */
/* Both section start and end are not needed to be pointer-aligned.     */
GC_API void GC_CALL GC_exclude_static_roots(void * /* low_address */,
                                            void * /* high_address_plus_1 */);

/* Clear the number of entries in the exclusion table.  Wizards only.   */
/* Should be called typically with the allocator lock held.             */
GC_API void GC_CALL GC_clear_exclusion_table(void);

/* Clear the set of root segments.  Wizards only.                       */
GC_API void GC_CALL GC_clear_roots(void);

/* Add a root segment.  Wizards only.                                   */
/* May merge adjacent or overlapping segments if appropriate.           */
/* Both segment start and end are not needed to be pointer-aligned.     */
/* low_address must not be greater than high_address_plus_1.            */
GC_API void GC_CALL GC_add_roots(void * /* low_address */,
                                 void * /* high_address_plus_1 */);

/* Remove root segments located fully in the region.  Wizards only.     */
GC_API void GC_CALL GC_remove_roots(void * /* low_address */,
                                    void * /* high_address_plus_1 */);

/* Add a displacement to the set of those considered valid by the       */
/* collector.  GC_register_displacement(n) means that if p was returned */
/* by GC_malloc, then (char *)p + n will be considered to be a valid    */
/* pointer to p.  N must be small and less than the size of p.          */
/* (All pointers to the interior of objects from the stack are          */
/* considered valid in any case.  This applies to heap objects and      */
/* static data.)                                                        */
/* Preferably, this should be called before any other GC procedures.    */
/* Calling it later adds to the probability of excess memory            */
/* retention.                                                           */
/* This is a no-op if the collector has recognition of                  */
/* arbitrary interior pointers enabled, which is now the default.       */
GC_API void GC_CALL GC_register_displacement(size_t /* n */);

/* The following version should be used if any debugging allocation is  */
/* being done.                                                          */
GC_API void GC_CALL GC_debug_register_displacement(size_t /* n */);

/* Explicitly trigger a full, world-stop collection.    */
GC_API void GC_CALL GC_gcollect(void);

/* Same as above but ignores the default stop_func setting and tries to */
/* unmap as much memory as possible (regardless of the corresponding    */
/* switch setting).  The recommended usage: on receiving a system       */
/* low-memory event; before retrying a system call failed because of    */
/* the system is running out of resources.                              */
GC_API void GC_CALL GC_gcollect_and_unmap(void);

/* Trigger a full world-stopped collection.  Abort the collection if    */
/* and when stop_func returns a nonzero value.  Stop_func will be       */
/* called frequently, and should be reasonably fast.  (stop_func is     */
/* called with the allocator lock held and the world might be stopped;  */
/* it's not allowed for stop_func to manipulate pointers to the garbage */
/* collected heap or call most of GC functions.)  This works even       */
/* if virtual dirty bits, and hence incremental collection is not       */
/* available for this architecture.  Collections can be aborted faster  */
/* than normal pause times for incremental collection.  However,        */
/* aborted collections do no useful work; the next collection needs     */
/* to start from the beginning.  stop_func must not be 0.               */
/* GC_try_to_collect() returns 0 if the collection was aborted (or the  */
/* collections are disabled), 1 if it succeeded.                        */
typedef int(GC_CALLBACK *GC_stop_func)(void);
GC_API int GC_CALL GC_try_to_collect(GC_stop_func /* stop_func */)
    GC_ATTR_NONNULL(1);

/* Set and get the default stop_func.  The default stop_func is used by */
/* GC_gcollect() and by implicitly triggered collections (except for    */
/* the case when handling out of memory).  Must not be 0.  Both the     */
/* setter and the getter acquire the allocator lock (in the reader mode */
/* in case of the getter) to avoid data race.                           */
GC_API void GC_CALL GC_set_stop_func(GC_stop_func /* stop_func */)
    GC_ATTR_NONNULL(1);
GC_API GC_stop_func GC_CALL GC_get_stop_func(void);

/* Return the number of bytes in the heap.  Excludes collector private  */
/* data structures.  Excludes the unmapped memory (returned to the OS). */
/* Includes empty blocks and fragmentation loss.  Includes some pages   */
/* that were allocated but never written.  This is an unsynchronized    */
/* getter, so it should be called typically with the allocator lock     */
/* held, at least in the reader mode, to avoid data race on             */
/* multiprocessors (the alternative way is to use GC_get_prof_stats or  */
/* GC_get_heap_usage_safe API calls instead).                           */
/* This getter remains lock-free (unsynchronized) for compatibility     */
/* reason since some existing clients call it from a GC callback        */
/* holding the allocator lock.  (This API function and the following    */
/* four ones below were made thread-safe in GC v7.2alpha1 and           */
/* reverted back in v7.2alpha7 for the reason described.)               */
GC_API size_t GC_CALL GC_get_heap_size(void);

/* Return a lower bound on the number of free bytes in the heap         */
/* (excluding the unmapped memory space).  This is an unsynchronized    */
/* getter (see GC_get_heap_size comment regarding thread-safety).       */
GC_API size_t GC_CALL GC_get_free_bytes(void);

/* Return the size (in bytes) of the unmapped memory (which is returned */
/* to the OS but could be remapped back by the collector later unless   */
/* the OS runs out of system/virtual memory). This is an unsynchronized */
/* getter (see GC_get_heap_size comment regarding thread-safety).       */
GC_API size_t GC_CALL GC_get_unmapped_bytes(void);

/* Return the number of bytes allocated since the last collection.      */
/* This is an unsynchronized getter (see GC_get_heap_size comment       */
/* regarding thread-safety).                                            */
GC_API size_t GC_CALL GC_get_bytes_since_gc(void);

/* Return the number of explicitly deallocated bytes of memory since    */
/* the recent collection.  This is an unsynchronized getter.            */
GC_API size_t GC_CALL GC_get_expl_freed_bytes_since_gc(void);

/* Return the total number of bytes allocated in this process.          */
/* Never decreases, except due to wrapping.  This is an unsynchronized  */
/* getter (see GC_get_heap_size comment regarding thread-safety).       */
GC_API size_t GC_CALL GC_get_total_bytes(void);

/* Return the total number of bytes obtained from OS.  Includes the     */
/* unmapped memory.  Never decreases.  It is an unsynchronized getter.  */
GC_API size_t GC_CALL GC_get_obtained_from_os_bytes(void);

/* Return the heap usage information.  This is a thread-safe (atomic)   */
/* alternative for the five above getters.   (This function acquires    */
/* the allocator lock in the reader mode, thus preventing data race and */
/* returning the consistent result.)  Passing NULL pointer is allowed   */
/* for any argument.  Returned (filled in) values are of word type.     */
GC_API void GC_CALL GC_get_heap_usage_safe(GC_word * /* pheap_size */,
                                           GC_word * /* pfree_bytes */,
                                           GC_word * /* punmapped_bytes */,
                                           GC_word * /* pbytes_since_gc */,
                                           GC_word * /* ptotal_bytes */);

/* Structure used to query GC statistics (profiling information).       */
/* More fields could be added in the future.  To preserve compatibility */
/* new fields should be added only to the end, and no deprecated fields */
/* should be removed from.                                              */
struct GC_prof_stats_s {
  /* Heap size in bytes (including the area unmapped to OS).  */
  /* Same as GC_get_heap_size() + GC_get_unmapped_bytes().    */
  GC_word heapsize_full;

  /* Total bytes contained in free and unmapped blocks.       */
  /* Same as GC_get_free_bytes() + GC_get_unmapped_bytes().   */
  GC_word free_bytes_full;

  /* Amount of memory unmapped to OS.  Same as the value      */
  /* returned by GC_get_unmapped_bytes().                     */
  GC_word unmapped_bytes;

  /* Number of bytes allocated since the recent collection.   */
  /* Same as returned by GC_get_bytes_since_gc().             */
  GC_word bytes_allocd_since_gc;

  /* Number of bytes allocated before the recent garbage      */
  /* collection.  The value may wrap.  Same as the result of  */
  /* GC_get_total_bytes() - GC_get_bytes_since_gc().          */
  GC_word allocd_bytes_before_gc;

  /* Number of bytes not considered candidates for garbage    */
  /* collection.  Same as returned by GC_get_non_gc_bytes().  */
  GC_word non_gc_bytes;

  /* Garbage collection cycle number.  The value may wrap     */
  /* (and could be -1).  Same as returned by GC_get_gc_no().  */
  GC_word gc_no;

  /* Number of marker threads (excluding the initiating one). */
  /* Same as returned by GC_get_parallel (or 0 if the         */
  /* collector is single-threaded).                           */
  GC_word markers_m1;

  /* Approximate number of reclaimed bytes after recent GC.   */
  GC_word bytes_reclaimed_since_gc;

  /* Approximate number of bytes reclaimed before the recent  */
  /* garbage collection.  The value may wrap.                 */
  GC_word reclaimed_bytes_before_gc;

  /* Number of bytes freed explicitly since the recent GC.    */
  /* Same as returned by GC_get_expl_freed_bytes_since_gc().  */
  GC_word expl_freed_bytes_since_gc;

  /* Total amount of memory obtained from OS, in bytes.       */
  GC_word obtained_from_os_bytes;
};

/* Atomically get GC statistics (various global counters).  Clients     */
/* should pass the size of the buffer (of GC_prof_stats_s type) to fill */
/* in the values - this is for interoperability between different GC    */
/* versions, an old client could have fewer fields, and vice versa,     */
/* client could use newer gc.h (with more entries declared in the       */
/* structure) than that of the linked GC library; in the latter case,   */
/* unsupported (unknown) fields are filled in with -1.  Return the size */
/* (in bytes) of the filled in part of the structure (excluding all     */
/* unknown fields, if any).                                             */
GC_API size_t GC_CALL GC_get_prof_stats(struct GC_prof_stats_s *,
                                        size_t /* stats_sz */);
#ifdef GC_THREADS
/* Same as above but unsynchronized (i.e., not holding the allocator  */
/* lock).  Clients should call it using GC_call_with_reader_lock() to */
/* avoid data race on multiprocessors.                                */
GC_API size_t GC_CALL GC_get_prof_stats_unsafe(struct GC_prof_stats_s *,
                                               size_t /* stats_sz */);
#endif

/* Get the element value (converted to bytes) at a given index of       */
/* size_map table which provides requested-to-actual allocation size    */
/* mapping.  Assumes the collector is initialized.  Returns -1 if the   */
/* index is out of size_map table bounds. Does not use synchronization, */
/* thus clients should call it using GC_call_with_reader_lock()         */
/* typically to avoid data race on multiprocessors.                     */
GC_API size_t GC_CALL GC_get_size_map_at(int i);

/* Return the total memory use (in bytes) by all allocated blocks.      */
/* The result is equal to GC_get_heap_size() - GC_get_free_bytes().     */
/* Acquires the allocator lock in the reader mode.                      */
GC_API GC_word GC_CALL GC_get_memory_use(void);

/* Disable garbage collection.  Even GC_gcollect calls will be          */
/* ineffective.                                                         */
GC_API void GC_CALL GC_disable(void);

/* Return 1 (true) if the garbage collection is disabled (i.e., the     */
/* value of GC_dont_gc is non-zero), 0 otherwise.  Does not acquire     */
/* the allocator lock.                                                  */
GC_API int GC_CALL GC_is_disabled(void);

/* Try to re-enable garbage collection.  GC_disable() and GC_enable()   */
/* calls nest.  Garbage collection is enabled if the number of calls to */
/* both functions is equal.                                             */
GC_API void GC_CALL GC_enable(void);

/* Select whether to use the manual VDB mode for the incremental        */
/* collection.  Has no effect if called after enabling the incremental  */
/* collection.  The default value is off unless the collector is        */
/* compiled with MANUAL_VDB defined.  The manual VDB mode should be     */
/* used only if the client has the appropriate GC_END_STUBBORN_CHANGE   */
/* and GC_reachable_here (or, alternatively, GC_PTR_STORE_AND_DIRTY)    */
/* calls (to ensure proper write barriers).  The setter and the getter  */
/* are not synchronized.                                                */
GC_API void GC_CALL GC_set_manual_vdb_allowed(int);
GC_API int GC_CALL GC_get_manual_vdb_allowed(void);

/* The constants to represent available VDB techniques. */

/* Means the incremental mode is unsupported.           */
#define GC_VDB_NONE 0

#define GC_VDB_MPROTECT 0x1

/* Means GC_set_manual_vdb_allowed(1) has effect.       */
#define GC_VDB_MANUAL 0x2

/* Means no other technique is usable.                  */
#define GC_VDB_DEFAULT 0x4

#define GC_VDB_GWW 0x8

#define GC_VDB_PROC 0x20
#define GC_VDB_SOFT 0x40

/* Get the list of available virtual dirty bits (VDB) techniques.       */
/* The returned value is a constant one, either GC_VDB_NONE, or one or  */
/* more of the above GC_VDB_* constants, or'ed together.  May be called */
/* before the collector is initialized.                                 */
GC_API unsigned GC_CALL GC_get_supported_vdbs(void);

/* Enable incremental/generational collection.  Not advisable unless    */
/* dirty bits are available or most heap objects are pointer-free       */
/* (atomic) or immutable.  Don't use in leak finding mode.  Ignored if  */
/* GC_dont_gc is non-zero.  Only the generational piece of this is      */
/* functional if GC_time_limit is set to GC_TIME_UNLIMITED.  Causes     */
/* thread-local variant of GC_gcj_malloc() to revert to locked          */
/* allocation.  Must be called before any such GC_gcj_malloc() calls.   */
/* For best performance, should be called as early as possible.         */
/* On some platforms, calling it later may have adverse effects.        */
/* Safe to call before the GC initialization; it performs the later if  */
/* not done yet.                                                        */
GC_API void GC_CALL GC_enable_incremental(void);

/* Return 1 (true) if the incremental mode is on, 0 otherwise.          */
/* Does not acquire the allocator lock.                                 */
GC_API int GC_CALL GC_is_incremental_mode(void);

/* An extended version of GC_is_incremental_mode() to return one of     */
/* GC_VDB_* constants designating which VDB technique is used exactly.  */
/* Does not acquire the allocator lock.                                 */
GC_API unsigned GC_CALL GC_get_actual_vdb(void);

/* May protect non-atomic objects.  */
#define GC_PROTECTS_POINTER_HEAP 1

#define GC_PROTECTS_PTRFREE_HEAP 2

/* Protects static data.  But this is currently never.          */
#define GC_PROTECTS_STATIC_DATA 4

/* Deprecated.  It is probably impractical to protect stacks.   */
#define GC_PROTECTS_STACK 8

#define GC_PROTECTS_NONE 0

/* Does incremental mode write-protect pages?  Returns zero or  */
/* more of the above GC_PROTECTS_*, or'ed together.             */
/* The collector is assumed to be initialized before this call. */
/* The result is not affected by GC_set_manual_vdb_allowed().   */
/* Call of GC_enable_incremental() may change the result to     */
/* GC_PROTECTS_NONE if some implementation is chosen at runtime */
/* not needing to write-protect the pages.                      */
GC_API int GC_CALL GC_incremental_protection_needs(void);

/* Force start of incremental collection.  Acquires the allocator lock. */
/* No-op unless the GC incremental mode is on.                          */
GC_API void GC_CALL GC_start_incremental_collection(void);

/* Perform some garbage collection work, if appropriate.        */
/* Return 0 if there is no more work to be done (including the  */
/* case when garbage collection is not appropriate).            */
/* Typically performs an amount of work corresponding roughly   */
/* to marking from one page.  May do more work if further       */
/* progress requires it, e.g. if incremental collection is      */
/* disabled.  It is reasonable to call this in a wait loop      */
/* until it returns 0.  If GC is disabled but the incremental   */
/* collection is already ongoing, then perform marking anyway   */
/* but not stopping the world (and without the reclaim phase).  */
GC_API int GC_CALL GC_collect_a_little(void);

/* Allocate an object of size lb bytes.  The client guarantees that as  */
/* long as the object is live, it will be referenced by a pointer that  */
/* points to somewhere within the first GC heap block (hblk) of the     */
/* object.  (This should normally be declared volatile to prevent the   */
/* compiler from invalidating this assertion.)  This routine is only    */
/* useful if a large array is being allocated.  It reduces the chance   */
/* of accidentally retaining such an array as a result of scanning an   */
/* integer that happens to be an address inside the array.  (Actually,  */
/* it reduces the chance of the allocator not finding space for such    */
/* an array, since it will try hard to avoid introducing such a false   */
/* reference.)  On a SunOS 4.X or Windows system this is recommended    */
/* for arrays likely to be larger than 100 KB or so.  For other systems,*/
/* or if the collector is not configured to recognize all interior      */
/* pointers, the threshold is normally much higher.                     */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_malloc_ignore_off_page(size_t /* lb */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_malloc_atomic_ignore_off_page(size_t /* lb */);

#if (defined(GC_CAN_SAVE_CALL_STACKS) || defined(GC_ADD_CALLER)) \
    && !defined(GC_RETURN_ADDR_T_DEFINED)
/* A type to hold a function return address (pointer).  Never used    */
/* for calling a function.                                            */
#  if defined(__GNUC__)
/* Define it as a data (object) pointer type to avoid the compiler  */
/* complain that ISO C forbids conversion between object and        */
/* function pointer types.                                          */
typedef void *GC_return_addr_t;
#  else
typedef void (*GC_return_addr_t)(void);
#  endif
#  define GC_RETURN_ADDR_T_DEFINED
#endif /* GC_CAN_SAVE_CALL_STACKS || GC_ADD_CALLER */

#ifdef GC_ADD_CALLER
#  define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__
#  define GC_EXTRA_PARAMS GC_return_addr_t ra, const char *s, int i
#else
#  define GC_EXTRAS __FILE__, __LINE__
#  define GC_EXTRA_PARAMS const char *s, int i
#endif

/* The following is only defined if the library has been suitably       */
/* compiled:                                                            */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_malloc_atomic_uncollectable(size_t /* size_in_bytes */);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_debug_malloc_atomic_uncollectable(size_t, GC_EXTRA_PARAMS);

/* Debugging (annotated) allocation.  GC_gcollect will check            */
/* objects allocated in this way for overwrites, etc.                   */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_debug_malloc(size_t /* size_in_bytes */, GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_debug_malloc_atomic(size_t /* size_in_bytes */, GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC char *GC_CALL GC_debug_strdup(const char *,
                                                    GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC char *GC_CALL GC_debug_strndup(const char *, size_t,
                                                     GC_EXTRA_PARAMS)
    GC_ATTR_NONNULL(1);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_debug_malloc_uncollectable(size_t /* size_in_bytes */, GC_EXTRA_PARAMS);
GC_API GC_ATTR_DEPRECATED void *GC_CALL
    GC_debug_malloc_stubborn(size_t /* size_in_bytes */, GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_debug_malloc_ignore_off_page(size_t /* size_in_bytes */,
                                    GC_EXTRA_PARAMS);
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_debug_malloc_atomic_ignore_off_page(size_t /* size_in_bytes */,
                                           GC_EXTRA_PARAMS);
GC_API void GC_CALL GC_debug_free(void *);
GC_API void *GC_CALL GC_debug_realloc(void * /* old_object */,
                                      size_t /* new_size_in_bytes */,
                                      GC_EXTRA_PARAMS)
    /* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2);
GC_API GC_ATTR_DEPRECATED void GC_CALL GC_debug_change_stubborn(const void *);
GC_API void GC_CALL GC_debug_end_stubborn_change(const void *)
    GC_ATTR_NONNULL(1);

/* Routines that allocate objects with debug information (like the      */
/* above), but just fill in dummy file and line number information.     */
/* Thus they can serve as drop-in malloc/realloc replacements.  This    */
/* can be useful for two reasons:                                       */
/* 1) It allows the collector to be built with DBG_HDRS_ALL defined     */
/*    even if some allocation calls come from 3rd party libraries       */
/*    that can't be recompiled.                                         */
/* 2) On some platforms, the file and line information is redundant,    */
/*    since it can be reconstructed from a stack trace.  On such        */
/*    platforms it may be more convenient not to recompile, e.g. for    */
/*    leak detection.  This can be accomplished by instructing the      */
/*    linker to replace malloc/realloc with these.                      */
GC_API GC_ATTR_MALLOC GC_ATTR_ALLOC_SIZE(1) void *GC_CALL
    GC_debug_malloc_replacement(size_t /* size_in_bytes */);
GC_API /* 'realloc' attr */ GC_ATTR_ALLOC_SIZE(2) void *GC_CALL
    GC_debug_realloc_replacement(void * /* object_addr */,
                                 size_t /* size_in_bytes */);

#ifdef __cplusplus
#  define GC_CAST_AWAY_CONST_PVOID(p) \
    reinterpret_cast</* no const */ void *>(reinterpret_cast<GC_uintptr_t>(p))
#else
#  define GC_CAST_AWAY_CONST_PVOID(p) \
    ((/* no const */ void *)(GC_uintptr_t)(p))
#endif

/* Convenient macros for disappearing links registration working both   */
/* for debug and non-debug allocated objects, and accepting interior    */
/* pointers to object.                                                  */
#define GC_GENERAL_REGISTER_DISAPPEARING_LINK_SAFE(link, obj) \
  GC_general_register_disappearing_link(                      \
      link, GC_base(GC_CAST_AWAY_CONST_PVOID(obj)))
#define GC_REGISTER_LONG_LINK_SAFE(link, obj) \
  GC_register_long_link(link, GC_base(GC_CAST_AWAY_CONST_PVOID(obj)))

#ifdef GC_DEBUG_REPLACEMENT
#  define GC_MALLOC(sz) GC_debug_malloc_replacement(sz)
#  define GC_REALLOC(old, sz) GC_debug_realloc_replacement(old, sz)
#elif defined(GC_DEBUG)
#  define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS)
#  define GC_REALLOC(old, sz) GC_debug_realloc(old, sz, GC_EXTRAS)
#else
#  define GC_MALLOC(sz) GC_malloc(sz)
#  define GC_REALLOC(old, sz) GC_realloc(old, sz)
#endif /* !GC_DEBUG_REPLACEMENT && !GC_DEBUG */

#ifdef GC_DEBUG
#  define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS)
#  define GC_STRDUP(s) GC_debug_strdup(s, GC_EXTRAS)
#  define GC_STRNDUP(s, sz) GC_debug_strndup(s, sz, GC_EXTRAS)
#  define GC_MALLOC_ATOMIC_UNCOLLECTABLE(sz) \
    GC_debug_malloc_atomic_uncollectable(sz, GC_EXTRAS)
#  define GC_MALLOC_UNCOLLECTABLE(sz) \
    GC_debug_malloc_uncollectable(sz, GC_EXTRAS)
#  define GC_MALLOC_IGNORE_OFF_PAGE(sz) \
    GC_debug_malloc_ignore_off_page(sz, GC_EXTRAS)
#  define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \
    GC_debug_malloc_atomic_ignore_off_page(sz, GC_EXTRAS)
#  define GC_FREE(p) GC_debug_free(p)
#  define GC_REGISTER_FINALIZER(p, f, d, of, od) \
    GC_debug_register_finalizer(p, f, d, of, od)
#  define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
    GC_debug_register_finalizer_ignore_self(p, f, d, of, od)
#  define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
    GC_debug_register_finalizer_no_order(p, f, d, of, od)
#  define GC_REGISTER_FINALIZER_UNREACHABLE(p, f, d, of, od) \
    GC_debug_register_finalizer_unreachable(p, f, d, of, od)
#  define GC_TOGGLEREF_ADD(p, is_strong) GC_debug_toggleref_add(p, is_strong)
#  define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p)
#  define GC_PTR_STORE_AND_DIRTY(p, q) GC_debug_ptr_store_and_dirty(p, q)
#  define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
    GC_GENERAL_REGISTER_DISAPPEARING_LINK_SAFE(link, obj)
#  define GC_REGISTER_LONG_LINK(link, obj) \
    GC_REGISTER_LONG_LINK_SAFE(link, obj)
#  define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n)
#else
#  define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz)
#  define GC_STRDUP(s) GC_strdup(s)
#  define GC_STRNDUP(s, sz) GC_strndup(s, sz)
#  define GC_MALLOC_ATOMIC_UNCOLLECTABLE(sz) GC_malloc_atomic_uncollectable(sz)
#  define GC_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(sz)
#  define GC_MALLOC_IGNORE_OFF_PAGE(sz) GC_malloc_ignore_off_page(sz)
#  define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \
    GC_malloc_atomic_ignore_off_page(sz)
#  define GC_FREE(p) GC_free(p)
#  define GC_REGISTER_FINALIZER(p, f, d, of, od) \
    GC_register_finalizer(p, f, d, of, od)
#  define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
    GC_register_finalizer_ignore_self(p, f, d, of, od)
#  define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
    GC_register_finalizer_no_order(p, f, d, of, od)
#  define GC_REGISTER_FINALIZER_UNREACHABLE(p, f, d, of, od) \
    GC_register_finalizer_unreachable(p, f, d, of, od)
#  define GC_TOGGLEREF_ADD(p, is_strong) GC_toggleref_add(p, is_strong)
#  define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p)
#  define GC_PTR_STORE_AND_DIRTY(p, q) GC_ptr_store_and_dirty(p, q)
#  define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
    GC_general_register_disappearing_link(link, obj)
#  define GC_REGISTER_LONG_LINK(link, obj) GC_register_long_link(link, obj)
#  define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n)
#endif /* !GC_DEBUG */

/* The following are included because they are often convenient, and    */
/* reduce the chance for a misspecified size argument.  But calls may   */
/* expand to something syntactically incorrect if t is a complicated    */
/* type expression.  Note that, unlike C++ new operator, these ones     */
/* may return NULL (if out of memory).                                  */
#define GC_NEW(t) ((t *)GC_MALLOC(sizeof(t)))
#define GC_NEW_ATOMIC(t) ((t *)GC_MALLOC_ATOMIC(sizeof(t)))
#define GC_NEW_UNCOLLECTABLE(t) ((t *)GC_MALLOC_UNCOLLECTABLE(sizeof(t)))

#ifdef GC_REQUIRE_WCSDUP
/* This might be unavailable on some targets (or not needed). */
/* wchar_t should be defined in stddef.h */
GC_API GC_ATTR_MALLOC wchar_t *GC_CALL GC_wcsdup(const wchar_t *)
    GC_ATTR_NONNULL(1);
GC_API GC_ATTR_MALLOC wchar_t *GC_CALL GC_debug_wcsdup(const wchar_t *,
                                                       GC_EXTRA_PARAMS)
    GC_ATTR_NONNULL(1);
#  ifdef GC_DEBUG
#    define GC_WCSDUP(s) GC_debug_wcsdup(s, GC_EXTRAS)
#  else
#    define GC_WCSDUP(s) GC_wcsdup(s)
#  endif
#endif /* GC_REQUIRE_WCSDUP */

/* Finalization.  Some of these primitives are grossly unsafe.          */
/* The idea is to make them both cheap, and sufficient to build         */
/* a safer layer, closer to Modula-3, Java, or PCedar finalization.     */
/* The interface represents my conclusions from a long discussion       */
/* with Alan Demers, Dan Greene, Carl Hauser, Barry Hayes,              */
/* Christian Jacobi, and Russ Atkinson.  It's not perfect, and          */
/* probably nobody else agrees with it.  Hans-J. Boehm  3/13/92         */
typedef void(GC_CALLBACK *GC_finalization_proc)(void * /* obj */,
                                                void * /* client_data */);

/* When obj is no longer accessible, invoke             */
/* (*fn)(obj, cd).  If a and b are inaccessible, and    */
/* a points to b (after disappearing links have been    */
/* made to disappear), then only a will be              */
/* finalized.  (If this does not create any new         */
/* pointers to b, then b will be finalized after the    */
/* next collection.)  Any finalizable object that       */
/* is reachable from itself by following one or more    */
/* pointers will not be finalized (or collected).       */
/* Thus cycles involving finalizable objects should     */
/* be avoided, or broken by disappearing links.         */
/* All but the last finalizer registered for an object  */
/* is ignored.                                          */
/* No-op in the leak-finding mode.                      */
/* Finalization may be removed by passing 0 as fn.      */
/* Finalizers are implicitly unregistered when they are */
/* enqueued for finalization (i.e. become ready to be   */
/* finalized).                                          */
/* The old finalizer and client data are stored in      */
/* *ofn and *ocd.  (ofn and/or ocd may be NULL.         */
/* The allocator lock is held while *ofn and *ocd are   */
/* updated.  In case of error (no memory to register    */
/* new finalizer), *ofn and *ocd remain unchanged.)     */
/* Fn is never invoked on an accessible object,         */
/* provided hidden pointers are converted to real       */
/* pointers only if the allocator lock is held, at      */
/* least in the reader mode, and such conversions are   */
/* not performed by finalization routines.              */
/* If GC_register_finalizer is aborted as a result of   */
/* a signal, the object may be left with no             */
/* finalization, even if neither the old nor new        */
/* finalizer were NULL.                                 */
/* Obj should be the starting address of an object      */
/* allocated by GC_malloc or friends. Obj may also be   */
/* NULL or point to something outside GC heap (in this  */
/* case, fn is ignored, *ofn and *ocd are set to NULL). */
/* Note that any garbage collectible object referenced  */
/* by cd will be considered accessible until the        */
/* finalizer is invoked.                                */
GC_API void GC_CALL GC_register_finalizer(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);

/* Another versions of the above follow.  It ignores            */
/* self-cycles, i.e. pointers from a finalizable object to      */
/* itself.  There is a stylistic argument that this is wrong,   */
/* but it's unavoidable for C++, since the compiler may         */
/* silently introduce these.  It's also benign in that specific */
/* case.  And it helps if finalizable objects are split to      */
/* avoid cycles.                                                */
/* Note that cd will still be viewed as accessible, even if it  */
/* refers to the object itself.                                 */
GC_API void GC_CALL GC_register_finalizer_ignore_self(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer_ignore_self(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);

/* Another version of the above.  It ignores all cycles.        */
/* It should probably only be used by Java implementations.     */
/* Note that cd will still be viewed as accessible, even if it  */
/* refers to the object itself.                                 */
GC_API void GC_CALL GC_register_finalizer_no_order(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer_no_order(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);

/* This is a special finalizer that is useful when an object's  */
/* finalizer must be run when the object is known to be no      */
/* longer reachable, not even from other finalizable objects.   */
/* It behaves like "normal" finalization, except that the       */
/* finalizer is not run while the object is reachable from      */
/* other objects specifying unordered finalization.             */
/* Effectively it allows an object referenced, possibly         */
/* indirectly, from an unordered finalizable object to override */
/* the unordered finalization request.                          */
/* This can be used in combination with finalizer_no_order so   */
/* as to release resources that must not be released while an   */
/* object can still be brought back to life by other            */
/* finalizers.                                                  */
/* Only works if GC_java_finalization is set.  Probably only    */
/* of interest when implementing a language that requires       */
/* unordered finalization (e.g. Java, C#).                      */
GC_API void GC_CALL GC_register_finalizer_unreachable(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);
GC_API void GC_CALL GC_debug_register_finalizer_unreachable(
    void * /* obj */, GC_finalization_proc /* fn */, void * /* cd */,
    GC_finalization_proc * /* ofn */, void ** /* ocd */) GC_ATTR_NONNULL(1);

/* A constant indicating a failure due to lack of memory.       */
#define GC_NO_MEMORY 2

/* The following routine may be used to break cycles between    */
/* finalizable objects, thus causing cyclic finalizable         */
/* objects to be finalized in the correct order.  Standard      */
/* use involves calling GC_register_disappearing_link(&p),      */
/* where p is a pointer that is not followed by finalization    */
/* code, and should not be considered in determining            */
/* finalization order.                                          */
/* Link should point to a field of a heap-allocated object obj. */
/* (*link) will be cleared when obj is found to be              */
/* inaccessible.  This happens before any finalization code is  */
/* invoked, and before any decisions about finalization order   */
/* are made.  This is useful in telling the finalizer that some */
/* pointers are not essential for proper finalization.  This    */
/* may avoid finalization cycles.  Note that obj may be         */
/* resurrected by another finalizer, and thus the clearing of   */
/* (*link) may be visible to non-finalization code.  There is   */
/* an argument that an arbitrary action should be allowed here, */
/* instead of just clearing a pointer.  But this causes         */
/* problems if that action alters, or examines connectivity.    */
/* Returns GC_DUPLICATE if link was already registered,         */
/* GC_SUCCESS if registration succeeded, GC_NO_MEMORY if it     */
/* failed for lack of memory (and GC_oom_fn did not handle the  */
/* problem).  Only exists for backward compatibility, use       */
/* GC_general_register_disappearing_link() instead.             */
GC_API int GC_CALL GC_register_disappearing_link(void ** /* link */)
    GC_ATTR_NONNULL(1);

/* A slight generalization of the above.  *link is      */
/* cleared when obj first becomes inaccessible.  This   */
/* can be used to implement weak pointers easily and    */
/* safely.  Typically link will point to a location     */
/* (in a GC-allocated object or not) holding            */
/* a disguised pointer to obj.  (A pointer inside       */
/* an "atomic" object is effectively disguised.)        */
/* In this way, weak pointers are broken before any     */
/* object reachable from them gets finalized.           */
/* Each link may be registered only with one obj value, */
/* i.e. all objects but the last one (link registered   */
/* with) are ignored.  This was added after a long      */
/* email discussion with John Ellis.                    */
/* link must be non-NULL (and be properly aligned).     */
/* obj must be a pointer to the beginning of an object  */
/* allocated by GC_malloc or friends.  A link           */
/* disappears when it is unregistered manually, or when */
/* (*link) is cleared, or when the object containing    */
/* this link is garbage collected.  It is unsafe to     */
/* explicitly deallocate the object containing link.    */
/* Explicit deallocation of obj may or may not cause    */
/* link to eventually be cleared.  No-op in the         */
/* leak-finding mode.  This function can be used to     */
/* implement certain types of weak pointers.  Note,     */
/* however, this generally requires that the allocator  */
/* lock is held, at least in the reader mode (e.g.      */
/* using GC_call_with_reader_lock), when the disguised  */
/* pointer is accessed.  Otherwise a strong pointer     */
/* could be recreated between the time the collector    */
/* decides to reclaim the object and the link is        */
/* cleared.  Returns GC_SUCCESS if registration         */
/* succeeded (a new link is registered), GC_DUPLICATE   */
/* if link was already registered (with some object),   */
/* GC_NO_MEMORY if registration failed for lack of      */
/* memory (and GC_oom_fn did not handle the problem),   */
/* GC_UNIMPLEMENTED if GC_find_leak is true.            */
GC_API int GC_CALL GC_general_register_disappearing_link(
    void ** /* link */, const void * /* obj */) GC_ATTR_NONNULL(1)
    GC_ATTR_NONNULL(2);

/* Moves a link previously registered via               */
/* GC_general_register_disappearing_link (or            */
/* GC_register_disappearing_link).  Does not change the */
/* target object of the weak reference.  Does not       */
/* change (*new_link) content.  May be called with      */
/* new_link equal to link (to check whether link has    */
/* been registered).  Returns GC_SUCCESS on success,    */
/* GC_DUPLICATE if there is already another             */
/* disappearing link at the new location (never         */
/* returned if new_link is equal to link), GC_NOT_FOUND */
/* if no link is registered at the original location.   */
GC_API int GC_CALL GC_move_disappearing_link(void ** /* link */,
                                             void ** /* new_link */)
    GC_ATTR_NONNULL(2);

/* Undoes a registration by either of the above two     */
/* routines.  Returns 0 if link was not actually        */
/* registered (otherwise returns 1).                    */
GC_API int GC_CALL GC_unregister_disappearing_link(void ** /* link */);

/* Similar to GC_general_register_disappearing_link but */
/* *link only gets cleared when obj becomes truly       */
/* inaccessible.  An object becomes truly inaccessible  */
/* when it can no longer be resurrected from its        */
/* finalizer (e.g. by assigning itself to a pointer     */
/* traceable from root).  This can be used to implement */
/* long weak pointers easily and safely.                */
GC_API int GC_CALL GC_register_long_link(void ** /* link */,
                                         const void * /* obj */)
    GC_ATTR_NONNULL(1) GC_ATTR_NONNULL(2);

/* Similar to GC_move_disappearing_link but for a link  */
/* previously registered via GC_register_long_link.     */
GC_API int GC_CALL GC_move_long_link(void ** /* link */,
                                     void ** /* new_link */)
    GC_ATTR_NONNULL(2);

/* Similar to GC_unregister_disappearing_link but for a */
/* registration by either of the above two routines.    */
GC_API int GC_CALL GC_unregister_long_link(void ** /* link */);

/* Support of toggle-ref style of external memory management    */
/* without hooking up to the host retain/release machinery.     */
/* The idea of toggle-ref is that an external reference to      */
/* an object is kept and it can be either a strong or weak      */
/* reference; a weak reference is used when the external peer   */
/* has no interest in the object, and a strong otherwise.       */
typedef enum {
  GC_TOGGLE_REF_DROP,
  GC_TOGGLE_REF_STRONG,
  GC_TOGGLE_REF_WEAK
} GC_ToggleRefStatus;

/* The callback is to decide (return) the new state of a given  */
/* object.  Invoked by the collector for all objects registered */
/* for toggle-ref processing.  Invoked with the allocator lock  */
/* held but the world is running.                               */
typedef GC_ToggleRefStatus(GC_CALLBACK *GC_toggleref_func)(void * /* obj */);

/* Set (register) a callback that decides the state of a given  */
/* object (by, probably, inspecting its native state).          */
/* The argument may be 0 (means no callback).  Both the setter  */
/* and the getter acquire the allocator lock (in the reader     */
/* mode in case of the getter).                                 */
GC_API void GC_CALL GC_set_toggleref_func(GC_toggleref_func);
GC_API GC_toggleref_func GC_CALL GC_get_toggleref_func(void);

/* Register a given object for toggle-ref processing.  It will  */
/* be stored internally and the toggle-ref callback will be     */
/* invoked on the object until the callback returns             */
/* GC_TOGGLE_REF_DROP or the object is collected.  If is_strong */
/* is true, then the object is registered with a strong ref,    */
/* a weak one otherwise.  Obj should be the starting address    */
/* of an object allocated by GC_malloc (GC_debug_malloc) or     */
/* friends.  Returns GC_SUCCESS if registration succeeded (or   */
/* no callback is registered yet), GC_NO_MEMORY if it failed    */
/* for a lack of memory reason.                                 */
GC_API int GC_CALL GC_toggleref_add(void * /* obj */, int /* is_strong */)
    GC_ATTR_NONNULL(1);
GC_API int GC_CALL GC_debug_toggleref_add(void * /* obj */,
                                          int /* is_strong */)
    GC_ATTR_NONNULL(1);

/* Finalizer callback support.  Invoked by the collector (with  */
/* the allocator lock held) for each unreachable object         */
/* enqueued for finalization.  Zero means no callback.          */
/* The setter and the getter acquire the allocator lock too (in */
/* the reader mode in case of the getter).                      */
typedef void(GC_CALLBACK *GC_await_finalize_proc)(void * /* obj */);
GC_API void GC_CALL GC_set_await_finalize_proc(GC_await_finalize_proc);
GC_API GC_await_finalize_proc GC_CALL GC_get_await_finalize_proc(void);

/* Returns !=0 if GC_invoke_finalizers has something to do.     */
/* Does not use any synchronization.                            */
GC_API int GC_CALL GC_should_invoke_finalizers(void);

/* Set maximum amount of finalizers to run during a single      */
/* invocation of GC_invoke_finalizers.  Zero means no limit.    */
/* Both the setter and the getter acquire the allocator lock    */
/* (in the reader mode in case of the getter).  Note that       */
/* invocation of GC_finalize_all resets the maximum amount      */
/* value.                                                       */
GC_API void GC_CALL GC_set_interrupt_finalizers(unsigned);
GC_API unsigned GC_CALL GC_get_interrupt_finalizers(void);

/* Run finalizers for all objects that are ready to     */
/* be finalized.  Return the number of finalizers       */
/* that were run.  Normally this is also called         */
/* implicitly during some allocations.  If              */
/* GC_finalize_on_demand is nonzero, it must be called  */
/* explicitly.                                          */
GC_API int GC_CALL GC_invoke_finalizers(void);

/* Explicitly tell the collector that an object is reachable    */
/* at a particular program point.  This prevents the argument   */
/* pointer from being optimized away, even it is otherwise no   */
/* longer needed.  It should have no visible effect in the      */
/* absence of finalizers or disappearing links.  But it may be  */
/* needed to prevent finalizers from running while the          */
/* associated external resource is still in use.                */
/* The function is sometimes called keep_alive in other         */
/* settings.                                                    */
#if defined(__GNUC__) && !defined(__INTEL_COMPILER) \
    && !(defined(__APPLE__) && defined(__arm__) && defined(__TINYC__))
/* TCC (as of v0.9.28rc) does not support asm on macOS/arm. */
#  if defined(__CHERI_PURE_CAPABILITY__) || defined(__TINYC__)
#    define GC_reachable_here(ptr) \
      __asm__ __volatile__(" " : : "g"(ptr) : "memory")
#  elif defined(__e2k__)
#    define GC_reachable_here(ptr) \
      __asm__ __volatile__(" " : : "r"(ptr) : "memory")
#  else
#    define GC_reachable_here(ptr) \
      __asm__ __volatile__(" " : : "X"(ptr) : "memory")
#  endif
#elif defined(LINT2)
/* The definition is similar to that of COVERT_DATAFLOW().    */
#  define GC_reachable_here(ptr) GC_noop1(~(GC_word)(ptr) ^ (~(GC_word)0))
#else
#  define GC_reachable_here(ptr) GC_noop1_ptr(GC_CAST_AWAY_CONST_PVOID(ptr))
#endif

/* Make the argument of word type appear live to compiler.  This could  */
/* be used to prevent certain compiler false positive (FP) warnings and */
/* misoptimizations.  Should be robust against the whole program        */
/* analysis.                                                            */
GC_API void GC_CALL GC_noop1(GC_word);

/* Same as GC_noop1() but for a pointer.        */
GC_API void GC_CALL GC_noop1_ptr(volatile void *);

/* GC_set_warn_proc can be used to redirect or filter warning messages. */
/* p may not be a NULL pointer.  msg is printf format string (arg must  */
/* match the format).  Both the setter and the getter acquire the       */
/* allocator lock (in the reader mode in case of the getter) to avoid   */
/* data race.  In GC v7.1 and before: the setter returned the value of  */
/* old warn_proc.  In GC v8.2.x and before: msg pointer type had no     */
/* const qualifier.                                                     */
typedef void(GC_CALLBACK *GC_warn_proc)(const char * /* msg */,
                                        GC_uintptr_t /* arg */);
GC_API void GC_CALL GC_set_warn_proc(GC_warn_proc /* p */) GC_ATTR_NONNULL(1);
GC_API GC_warn_proc GC_CALL GC_get_warn_proc(void);

/* GC_ignore_warn_proc may be used as an argument for GC_set_warn_proc  */
/* to suppress all warnings (unless statistics printing is turned on).  */
GC_API void GC_CALLBACK GC_ignore_warn_proc(const char *, GC_uintptr_t);

/* Change file descriptor of the GC log.  Unavailable on some targets.  */
GC_API void GC_CALL GC_set_log_fd(int);

/* abort_func is invoked on GC fatal aborts (just before OS-dependent   */
/* abort or exit(1) is called).  Must be non-NULL.  The default one     */
/* outputs msg to stderr provided msg is non-NULL.  msg is NULL if      */
/* invoked before exit(1) otherwise msg is non-NULL (i.e., if invoked   */
/* before abort).  Both the setter and the getter acquire the allocator */
/* lock (in the reader mode in case of the getter).  The setter does    */
/* not change abort_func if the library has been compiled with          */
/* SMALL_CONFIG defined.                                                */
typedef void(GC_CALLBACK *GC_abort_func)(const char * /* msg */);
GC_API void GC_CALL GC_set_abort_func(GC_abort_func) GC_ATTR_NONNULL(1);
GC_API GC_abort_func GC_CALL GC_get_abort_func(void);

/* A portable way to abort the application because of not enough        */
/* memory.                                                              */
GC_API void GC_CALL GC_abort_on_oom(void);

/* The following is intended to be used by a higher level (e.g.         */
/* Java-like) finalization facility.  It is expected that finalization  */
/* code will arrange for hidden pointers to disappear.  Otherwise,      */
/* objects can be accessed after they have been collected.  Should not  */
/* be used in the leak-finding mode.                                    */
/* Note that putting pointers in atomic objects or in non-pointer slots */
/* of "typed" objects is equivalent to disguising them in this way, and */
/* may have other advantages.  Note also that some code relies on that  */
/* the least significant bit of the argument (including for NULL) is    */
/* inverted by these primitives.                                        */
/* Important: converting a hidden pointer to a real pointer requires    */
/* verifying that the object still exists; this should involve          */
/* acquiring the allocator lock, at least in the reader mode, to avoid  */
/* a race with the collector (e.g., one thread might fetch hidden link  */
/* value, while another thread might collect the relevant object and    */
/* reuse the free space for another object).                            */
typedef GC_uintptr_t GC_hidden_pointer;
#define GC_HIDE_POINTER(p) (~(GC_hidden_pointer)(p))
#define GC_REVEAL_POINTER(p) ((void *)GC_HIDE_POINTER(p))

#if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS)
/* This exists only for compatibility (the GC-prefixed symbols are    */
/* preferred for new code).                                           */
#  define HIDE_POINTER(p) GC_HIDE_POINTER(p)
#  define REVEAL_POINTER(p) GC_REVEAL_POINTER(p)
#endif

/* A slightly modified version of GC_HIDE_POINTER which guarantees not  */
/* to "hide" NULL (i.e. passing zero argument gives zero result).  This */
/* might be useful in conjunction with GC_register_disappearing_link.   */
/* Note that unlike GC_HIDE_POINTER, inversion of the least significant */
/* bit of the argument is not guaranteed.                               */
#if defined(__CHERI_PURE_CAPABILITY__)
#  define GC_HIDE_NZ_POINTER(p) ((GC_hidden_pointer)(-(intptr_t)(p)))
#else
#  define GC_HIDE_NZ_POINTER(p) ((GC_hidden_pointer)(-(GC_signed_word)(p)))
#endif
#define GC_REVEAL_NZ_POINTER(p) ((void *)GC_HIDE_NZ_POINTER(p))

/* The routines to acquire/release the GC (allocator) lock.             */
/* The lock is not reentrant.  GC_alloc_unlock() should not be called   */
/* unless the allocator lock is acquired by the current thread.         */
#ifdef GC_THREADS
GC_API void GC_CALL GC_alloc_lock(void);
GC_API void GC_CALL GC_alloc_unlock(void);
#else
/* No need for real locking if the client is single-threaded.         */
#  define GC_alloc_lock() (void)0
#  define GC_alloc_unlock() (void)0
#endif /* !GC_THREADS */

typedef void *(GC_CALLBACK *GC_fn_type)(void * /* client_data */);

/* Execute given function with the allocator lock held (in the          */
/* exclusive mode).                                                     */
GC_API void *GC_CALL GC_call_with_alloc_lock(GC_fn_type /* fn */,
                                             void * /* client_data */)
    GC_ATTR_NONNULL(1);

/* Execute given function with the allocator lock held in the reader    */
/* (shared) mode.  The 3rd argument (release), if non-zero, indicates   */
/* that fn wrote some data that should be made visible to the thread    */
/* which acquires the allocator lock in the exclusive mode later.       */
#ifdef GC_THREADS
GC_API void *GC_CALL GC_call_with_reader_lock(GC_fn_type /* fn */,
                                              void * /* client_data */,
                                              int /* release */)
    GC_ATTR_NONNULL(1);
#else
#  define GC_call_with_reader_lock(fn, cd, r) ((void)(r), (fn)(cd))
#endif

/* These routines are intended to explicitly notify the collector       */
/* of new threads.  Often this is unnecessary because thread creation   */
/* is implicitly intercepted by the collector, using header-file        */
/* defines, or linker-based interception.  In the long run the intent   */
/* is to always make redundant registration safe.  In the short run,    */
/* this is being implemented a platform at a time.                      */
/* The interface is complicated by the fact that we probably will not   */
/* ever be able to automatically determine the stack bottom for thread  */
/* stacks on all platforms.                                             */

/* Structure representing the bottom (cold end) of a thread stack.      */
/* On most platforms this contains just a single address.               */
struct GC_stack_base {
  void *mem_base; /* the bottom of the general-purpose stack */
#if defined(__e2k__) || defined(__ia64) || defined(__ia64__) \
    || defined(_M_IA64)
  /* The bottom of the register stack.        */
  void *reg_base;
#endif
};

typedef void *(GC_CALLBACK *GC_stack_base_func)(
    struct GC_stack_base * /* sb */, void * /* arg */);

/* Call a function with a stack base structure corresponding to         */
/* somewhere in the GC_call_with_stack_base frame.  This often can      */
/* be used to provide a sufficiently accurate stack bottom.  And we     */
/* implement it everywhere.                                             */
GC_API void *GC_CALL GC_call_with_stack_base(GC_stack_base_func /* fn */,
                                             void * /* arg */)
    GC_ATTR_NONNULL(1);

#define GC_SUCCESS 0

/* Means was already registered.                */
#define GC_DUPLICATE 1

/* Deprecated.  No thread support in GC.        */
#define GC_NO_THREADS 2

/* Not yet implemented on this platform.        */
#define GC_UNIMPLEMENTED 3

/* Requested link not found (returned by GC_move_disappearing_link).    */
#define GC_NOT_FOUND 4

/* Start the parallel marker threads, if available.  Useful, e.g.,      */
/* after POSIX fork in a child process (provided not followed by exec)  */
/* or in single-threaded clients (provided it is OK for the client to   */
/* perform marking in parallel).  Acquires the allocator lock to avoid  */
/* a race.                                                              */
GC_API void GC_CALL GC_start_mark_threads(void);

#if defined(GC_DARWIN_THREADS) || defined(GC_WIN32_THREADS)
/* Use implicit thread registration and processing (via Win32 DllMain */
/* or Darwin task_threads).  Deprecated.  Must be called before       */
/* GC_INIT() and other GC routines.  Performs the GC initialization.  */
/* Should be avoided if GC_pthread_create, GC_beginthreadex (or       */
/* GC_CreateThread), or GC_register_my_thread could be used instead.  */
/* Disables parallelized garbage collection on Win32.                 */
GC_API void GC_CALL GC_use_threads_discovery(void);
#endif

#ifdef GC_THREADS
/* Suggest the GC to use the specific signal to suspend threads.      */
/* Has no effect after the GC initialization and on non-POSIX         */
/* systems.                                                           */
GC_API void GC_CALL GC_set_suspend_signal(int);

/* Suggest the GC to use the specific signal to resume threads.       */
/* Has no effect after the GC initialization and on non-POSIX         */
/* systems.  The same signal might be used for threads suspension     */
/* and restart.                                                       */
GC_API void GC_CALL GC_set_thr_restart_signal(int);

/* Return the signal number (which is a constant after the GC         */
/* initialization) used by the GC to suspend threads on POSIX         */
/* systems.  Return -1 otherwise.                                     */
GC_API int GC_CALL GC_get_suspend_signal(void);

/* Return the signal number (which is a constant after the GC         */
/* initialization) used by the GC to restart (resume) threads on      */
/* POSIX systems.  Return -1 otherwise.                               */
GC_API int GC_CALL GC_get_thr_restart_signal(void);

/* Explicitly enable GC_register_my_thread() invocation.              */
/* Done implicitly if a GC thread-creation function is called (or     */
/* implicit thread registration is activated, or the collector is     */
/* compiled with GC_ALWAYS_MULTITHREADED defined).  Otherwise, it     */
/* must be called from the main (or any previously registered) thread */
/* between the collector initialization and the first explicit        */
/* registering of a thread (it should be called as late as possible). */
/* Includes a GC_start_mark_threads() call.                           */
GC_API void GC_CALL GC_allow_register_threads(void);

/* Register the current thread, with the indicated stack bottom, as   */
/* a new thread whose stack(s) should be traced by the GC.  If it     */
/* is not implicitly called by the GC, this must be called before a   */
/* thread can allocate garbage collected memory, or assign pointers   */
/* to the garbage collected heap.  Once registered, a thread will be  */
/* stopped during garbage collections.                                */
/* This call must be previously enabled (see above).                  */
/* This should never be called from the main thread, where it is      */
/* always done implicitly.  This is normally done implicitly if GC_   */
/* functions are called to create the thread, e.g. by including gc.h  */
/* (which redefines some system functions) before calling the system  */
/* thread creation function.  Nonetheless, thread cleanup routines    */
/* (e.g., pthread key destructor) typically require manual thread     */
/* registering (and unregistering) if pointers to GC-allocated        */
/* objects are manipulated inside.                                    */
/* It is also always done implicitly on some platforms if             */
/* GC_use_threads_discovery() is called at start-up.  Except for the  */
/* latter case, the explicit call is normally required for threads    */
/* created by third-party libraries.                                  */
/* A manually registered thread requires manual unregistering.        */
/* Returns GC_SUCCESS on success, GC_DUPLICATE if already registered. */
GC_API int GC_CALL GC_register_my_thread(const struct GC_stack_base *)
    GC_ATTR_NONNULL(1);

/* Return 1 (true) if the calling (current) thread is registered with */
/* the garbage collector, 0 otherwise.  Acquires the allocator lock   */
/* in the reader mode.  If the thread is finished (e.g. running in    */
/* a destructor and not registered manually again), it is considered  */
/* as not registered.                                                 */
GC_API int GC_CALL GC_thread_is_registered(void);

/* Notify the collector about the stack and the alt-stack of the      */
/* current thread.  normstack and normstack_size are used to          */
/* determine the "normal" stack boundaries when a thread is suspended */
/* while it is on an alt-stack.  Acquires the allocator lock in the   */
/* reader mode.                                                       */
GC_API void GC_CALL GC_register_altstack(void * /* normstack */,
                                         size_t /* normstack_size */,
                                         void * /* altstack */,
                                         size_t /* altstack_size */);

/* Unregister the current thread.  Only an explicitly registered      */
/* thread (i.e. for which GC_register_my_thread() returns GC_SUCCESS) */
/* is allowed (and required) to call this function.  (As a special    */
/* exception, it is also allowed to once unregister the main thread.) */
/* The thread may no longer allocate garbage collected memory or      */
/* manipulate pointers to the garbage collected heap after making     */
/* this call.  Specifically, if it wants to return or otherwise       */
/* communicate a pointer to the garbage-collected heap to another     */
/* thread, it must do this before calling GC_unregister_my_thread,    */
/* most probably by saving it in a global data structure.  Must not   */
/* be called inside a GC callback function (except for                */
/* GC_call_with_stack_base() one).  Always returns GC_SUCCESS.        */
GC_API int GC_CALL GC_unregister_my_thread(void);

/* Stop/start the world explicitly.  Not recommended for general use. */
GC_API void GC_CALL GC_stop_world_external(void);
GC_API void GC_CALL GC_start_world_external(void);

/* Provide a verifier/modifier of the stack pointer when pushing the  */
/* thread stacks.  This might be useful for a crude integration       */
/* with certain coroutine implementations.  (*sp_ptr) is the captured */
/* stack pointer of the suspended thread with pthread_id (the latter  */
/* is actually of pthread_t type).  The functionality is unsupported  */
/* on some targets (the getter always returns 0 in such a case).      */
/* Both the setter and the getter acquire the allocator lock (in the  */
/* reader mode in case of the getter).  The client function (if       */
/* provided) is called with the allocator lock held and, might be,    */
/* with the world stopped.                                            */
typedef void(GC_CALLBACK *GC_sp_corrector_proc)(void ** /* sp_ptr */,
                                                void * /* pthread_id */);
GC_API void GC_CALL GC_set_sp_corrector(GC_sp_corrector_proc);
GC_API GC_sp_corrector_proc GC_CALL GC_get_sp_corrector(void);
#endif /* GC_THREADS */

/* Wrapper for functions that are likely to block (or, at least, do not */
/* allocate garbage collected memory and/or manipulate pointers to the  */
/* garbage collected heap) for an appreciable length of time.  While fn */
/* is running, the collector is said to be in the "inactive" state for  */
/* the current thread (this means that the thread is not suspended and  */
/* the thread's stack frames "belonging" to the functions in the        */
/* "inactive" state are not scanned during garbage collections).  It is */
/* assumed that the collector is already initialized and the current    */
/* thread is registered.  It is allowed for fn to call                  */
/* GC_call_with_gc_active() (even recursively), thus temporarily        */
/* toggling the collector's state back to "active".  The latter         */
/* technique might be used to make stack scanning more precise (i.e.    */
/* scan only stack frames of functions that allocate garbage collected  */
/* memory and/or manipulate pointers to the garbage collected heap).    */
/* Acquires the allocator lock in the reader mode (but fn is called     */
/* not holding it).                                                     */
GC_API void *GC_CALL GC_do_blocking(GC_fn_type /* fn */,
                                    void * /* client_data */)
    GC_ATTR_NONNULL(1);

/* Call a function switching to the "active" state of the collector for */
/* the current thread (i.e. the user function is allowed to call any    */
/* GC function and/or manipulate pointers to the garbage collected      */
/* heap).  GC_call_with_gc_active() has the functionality opposite to   */
/* GC_do_blocking() one.  It is assumed that the collector is already   */
/* initialized and the current thread is registered.  fn may toggle     */
/* the collector thread's state temporarily to "inactive" one by using  */
/* GC_do_blocking.  GC_call_with_gc_active() often can be used to       */
/* provide a sufficiently accurate stack bottom.  Acquires the          */
/* allocator lock in the reader mode (but fn is called not holding it). */
GC_API void *GC_CALL GC_call_with_gc_active(GC_fn_type /* fn */,
                                            void * /* client_data */)
    GC_ATTR_NONNULL(1);

/* Attempt to fill in the GC_stack_base structure with the stack bottom */
/* for this thread.  This appears to be required to implement anything  */
/* like the JNI AttachCurrentThread in an environment in which new      */
/* threads are not automatically registered with the collector.         */
/* It is also unfortunately hard to implement well on many platforms.   */
/* Returns GC_SUCCESS or GC_UNIMPLEMENTED.  Acquires the allocator lock */
/* on some platforms.                                                   */
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *)
    GC_ATTR_NONNULL(1);

/* Fill in the GC_stack_base structure with the cold end (bottom) of    */
/* the stack of the current thread (or coroutine).                      */
/* Unlike GC_get_stack_base, it retrieves the value stored in the       */
/* collector (which is initially set by the collector upon the thread   */
/* is started or registered manually but it could be later updated by   */
/* client using GC_set_stackbottom).  Returns the GC-internal non-NULL  */
/* handle of the thread which could be passed to GC_set_stackbottom     */
/* later.  It is assumed that the collector is already initialized and  */
/* the thread is registered.  Acquires the allocator lock in the reader */
/* mode.                                                                */
GC_API void *GC_CALL GC_get_my_stackbottom(struct GC_stack_base *)
    GC_ATTR_NONNULL(1);

/* Set the cool end of the user (coroutine) stack of the specified      */
/* thread.  The GC thread handle is either the one returned by          */
/* GC_get_my_stackbottom or NULL (the latter designates the current     */
/* thread).  The caller should hold the allocator lock (e.g. using      */
/* GC_call_with_reader_lock with release argument set to 1), the reader */
/* mode should be enough typically, at least for the collector itself   */
/* (the client is responsible to avoid data race between this and       */
/* GC_get_my_stackbottom functions if the client acquires the allocator */
/* lock in the reader mode).  Also, the function could be used for      */
/* setting GC_stackbottom value (the bottom of the primordial thread)   */
/* before the collector is initialized (the allocator lock is not       */
/* needed to be acquired at all in this case).                          */
GC_API void GC_CALL GC_set_stackbottom(void * /* gc_thread_handle */,
                                       const struct GC_stack_base *)
    GC_ATTR_NONNULL(2);

/* The following routines are primarily intended for use with a         */
/* preprocessor which inserts calls to check C pointer arithmetic.      */
/* They indicate failure by invoking the corresponding _print_proc.     */

/* Checked pointer pre- and post- increment operations.  Note that      */
/* the second argument is in units of bytes, not multiples of the       */
/* object size.  This should either be invoked from a macro, or the     */
/* call should be automatically generated.                              */
GC_API void *GC_CALL GC_pre_incr(void **, ptrdiff_t /* how_much */)
    GC_ATTR_NONNULL(1);
GC_API void *GC_CALL GC_post_incr(void **, ptrdiff_t /* how_much */)
    GC_ATTR_NONNULL(1);

/* Check that p and q point to the same object.  GC_same_obj_print_proc */
/* is called (fail by default) if they do not.  Succeeds, as well, if   */
/* neither p nor q points to the heap.  (May succeed also if both p and */
/* q point to between heap objects.)  Returns the first argument.       */
/* (The returned value may be hard to use due to typing issues.  But if */
/* we had a suitable preprocessor...)  We assume this is somewhat       */
/* performance critical (it should not be called by production code,    */
/* of course, but it can easily make even debugging intolerably slow).  */
GC_API void *GC_CALL GC_same_obj(void * /* p */, void * /* q */);

/* Check that p is visible to the collector as a possibly pointer       */
/* containing location.  If it is not, invoke GC_is_visible_print_proc  */
/* (fail by default).  Always returns the argument.  May erroneously    */
/* succeed in hard cases.  The function is intended for debugging use   */
/* with untyped allocations.  (The idea is that it should be possible,  */
/* though slow, to add such a call to all indirect pointer stores.)     */
/* Currently useless for the multi-threaded worlds.                     */
GC_API void *GC_CALL GC_is_visible(void * /* p */);

/* Check that if p is a pointer to a heap page, then it points to       */
/* a valid displacement within a heap object.  If it is not, invoke     */
/* GC_is_valid_displacement_print_proc (fail by default).  Always       */
/* returns the argument.  Uninteresting with all-interior-pointers on.  */
/* Note that we do not acquire the allocator lock, since nothing        */
/* relevant about the header should change while we have a valid object */
/* pointer to the block.                                                */
GC_API void *GC_CALL GC_is_valid_displacement(void * /* p */);

/* Explicitly dump the GC state.  This is most often called from the    */
/* debugger, or by setting the GC_DUMP_REGULARLY environment variable,  */
/* but it may be useful to call it from client code during debugging.   */
/* The current collection number is printed in the header of the dump.  */
/* Acquires the allocator lock in the reader mode to avoid data race.   */
/* Defined only if the library has been compiled without NO_DEBUGGING.  */
GC_API void GC_CALL GC_dump(void);

/* The same as GC_dump but allows to specify the name of dump and does  */
/* not acquire the allocator lock.  If name is non-NULL, it is printed  */
/* to help identifying individual dumps.  Otherwise the current         */
/* collection number is used as the name.                               */
/* Defined only if the library has been compiled without NO_DEBUGGING.  */
GC_API void GC_CALL GC_dump_named(const char * /* name */);

/* Dump information about each block of every GC memory section.        */
/* Defined only if the library has been compiled without NO_DEBUGGING.  */
GC_API void GC_CALL GC_dump_regions(void);

/* Dump information about every registered disappearing link and        */
/* finalizable object.                                                  */
/* Defined only if the library has been compiled without NO_DEBUGGING.  */
GC_API void GC_CALL GC_dump_finalization(void);

/* Safer, but slow, pointer addition.  Probably useful mainly with      */
/* a preprocessor.  Useful only for heap pointers.                      */
/* Only the macros without trailing digits are meant to be used         */
/* by clients.  These are designed to model the available C pointer     */
/* arithmetic expressions.                                              */
/* Even then, these are probably more useful as                         */
/* documentation than as part of the API.                               */
/* Note that GC_PTR_ADD evaluates the first argument more than once.    */
#if defined(GC_DEBUG) && (defined(__GNUC__) || defined(__clang__))
#  define GC_PTR_ADD3(x, n, type_of_result) \
    ((type_of_result)GC_same_obj((x) + (n), (x)))
#  define GC_PRE_INCR3(x, n, type_of_result) \
    ((type_of_result)GC_pre_incr((void **)&(x), (n) * sizeof(*(x))))
#  define GC_POST_INCR3(x, n, type_of_result) \
    ((type_of_result)GC_post_incr((void **)&(x), (n) * sizeof(*(x))))
#  define GC_PTR_ADD(x, n) GC_PTR_ADD3(x, n, __typeof__(x))
#  define GC_PRE_INCR(x, n) GC_PRE_INCR3(x, n, __typeof__(x))
#  define GC_POST_INCR(x) GC_POST_INCR3(x, 1, __typeof__(x))
#  define GC_POST_DECR(x) GC_POST_INCR3(x, -1, __typeof__(x))
#else /* !GC_DEBUG || !__GNUC__ */
/* We can't do this right without typeof, which ANSI decided was not    */
/* sufficiently useful.  Without it we resort to the non-debug version. */
/* TODO: This should eventually support C++0x decltype. */
#  define GC_PTR_ADD(x, n) ((x) + (n))
#  define GC_PRE_INCR(x, n) ((x) += (n))
#  define GC_POST_INCR(x) ((x)++)
#  define GC_POST_DECR(x) ((x)--)
#endif /* !GC_DEBUG || !__GNUC__ */

/* Safer assignment of a pointer to a non-stack location.       */
#ifdef GC_DEBUG
#  define GC_PTR_STORE(p, q)              \
    (*(void **)GC_is_visible((void *)(p)) \
     = GC_is_valid_displacement((void *)(q)))
#else
#  define GC_PTR_STORE(p, q) (*(void **)(p) = (void *)(q))
#endif

/* GC_PTR_STORE_AND_DIRTY(p,q) is equivalent to GC_PTR_STORE(p,q)       */
/* followed by GC_END_STUBBORN_CHANGE(p) and GC_reachable_here(q)       */
/* (assuming p and q do not have side effects).                         */
GC_API void GC_CALL GC_ptr_store_and_dirty(void * /* p */,
                                           const void * /* q */);
GC_API void GC_CALL GC_debug_ptr_store_and_dirty(void * /* p */,
                                                 const void * /* q */);

#ifdef GC_PTHREADS
/* For pthread support, we generally need to intercept a number of    */
/* thread library calls.  We do that here by macro defining them.     */
#  ifdef __cplusplus
} /* extern "C" */
#  endif
#  include "gc_pthread_redirects.h"
#  ifdef __cplusplus
extern "C" {
#  endif
#endif

/* This returns a list of objects with the link pointer located at the  */
/* beginning of each object.  The use of such list can greatly reduce   */
/* lock contention problems, since the allocator lock can be acquired   */
/* and released many fewer times.  Note that there is no "atomic"       */
/* version of this function, as otherwise the links would not be seen   */
/* by the collector.  If the argument is zero, then it is treated as 1. */
GC_API GC_ATTR_MALLOC void *GC_CALL GC_malloc_many(size_t /* lb */);

/* Retrieve the next element in the list returned by GC_malloc_many().  */
#define GC_NEXT(p) (*(void **)(p))

/* A filter function to control the scanning of dynamic libraries.      */
/* If implemented, called by GC before registering a dynamic library    */
/* (discovered by GC) section as a static data root (called only as     */
/* a last reason not to register).  The filename of the library, the    */
/* address and the length of the memory region (section) are passed.    */
/* This routine should return nonzero if that region should be scanned. */
/* Always called with the allocator lock held.  Depending on the        */
/* platform, might be called with the "world" stopped.                  */
typedef int(GC_CALLBACK *GC_has_static_roots_func)(
    const char * /* dlpi_name */, void * /* section_start */,
    size_t /* section_size */);

/* Register a new callback (a user-supplied filter) to control the      */
/* scanning of dynamic libraries.  Replaces any previously registered   */
/* callback.  May be 0 (means no filtering).  May be unused on some     */
/* platforms (if the filtering is unimplemented or inappropriate).      */
GC_API void
    GC_CALL GC_register_has_static_roots_callback(GC_has_static_roots_func);

#if !defined(CPPCHECK) && !defined(GC_WINDOWS_H_INCLUDED) && defined(WINAPI)
/* windows.h is included before gc.h */
#  define GC_WINDOWS_H_INCLUDED
#endif

#if defined(GC_WIN32_THREADS)                      \
    && (!defined(GC_PTHREADS) || defined(GC_BUILD) \
        || defined(GC_WINDOWS_H_INCLUDED))
/* Note: for Cygwin and pthreads-win32, this is skipped */
/* unless windows.h is included before gc.h.            */

#  if (!defined(GC_NO_THREAD_DECLS) || defined(GC_BUILD)) \
      && !defined(GC_DONT_INCL_WINDOWS_H)

#    ifdef __cplusplus
} /* Including windows.h in an extern "C" context no longer works. */
#    endif

#    if !defined(_WIN32_WCE) && !defined(__CEGCC__)
#      include <process.h> /* For _beginthreadex, _endthreadex */
#    endif

#    if defined(GC_BUILD) || !defined(GC_DONT_INCLUDE_WINDOWS_H)
#      include <windows.h>
#      define GC_WINDOWS_H_INCLUDED
#    endif

#    ifdef __cplusplus
extern "C" {
#    endif

#    ifdef GC_UNDERSCORE_STDCALL
/* Explicitly prefix exported/imported WINAPI (__stdcall) symbols */
/* with '_' (underscore).  Might be useful if MinGW/x86 is used.  */
#      define GC_CreateThread _GC_CreateThread
#      define GC_ExitThread _GC_ExitThread
#    endif

#    ifndef DECLSPEC_NORETURN
/* Typically defined in winnt.h. */
#      ifdef GC_WINDOWS_H_INCLUDED
#        define DECLSPEC_NORETURN /* empty */
#      else
#        define DECLSPEC_NORETURN __declspec(noreturn)
#      endif
#    endif

#    ifdef _WIN64
#      define GC_WIN32_SIZE_T GC_uintptr_t
#    elif defined(GC_WINDOWS_H_INCLUDED)
#      define GC_WIN32_SIZE_T DWORD
#    else
#      define GC_WIN32_SIZE_T unsigned long
#    endif

#    ifdef GC_INSIDE_DLL
/* Export GC DllMain to be invoked from client DllMain.   */
#      ifdef GC_UNDERSCORE_STDCALL
#        define GC_DllMain _GC_DllMain
#      endif
#      ifdef GC_WINDOWS_H_INCLUDED
GC_API BOOL WINAPI GC_DllMain(HINSTANCE /* inst */, ULONG /* reason */,
                              LPVOID /* reserved */);
#      else
GC_API int __stdcall GC_DllMain(void *, unsigned long, void *);
#      endif
#    endif /* GC_INSIDE_DLL */

/* All threads must be created using GC_CreateThread or             */
/* GC_beginthreadex, or must explicitly call GC_register_my_thread  */
/* (and call GC_unregister_my_thread before thread termination), so */
/* that they will be recorded in the thread table.  For backward    */
/* compatibility, it is possible to build the GC with GC_DLL        */
/* defined, and to call GC_use_threads_discovery.  This implicitly  */
/* registers all created threads, but appears to be less robust.    */
/* Currently the collector expects all threads to fall through and  */
/* terminate normally, or call GC_endthreadex() or GC_ExitThread,   */
/* so that the thread is properly unregistered.                     */
#    ifdef GC_WINDOWS_H_INCLUDED
GC_API HANDLE WINAPI GC_CreateThread(
    LPSECURITY_ATTRIBUTES /* lpThreadAttributes */,
    GC_WIN32_SIZE_T /* dwStackSize */,
    LPTHREAD_START_ROUTINE /* lpStartAddress */, LPVOID /* lpParameter */,
    DWORD /* dwCreationFlags */, LPDWORD /* lpThreadId */);

GC_API DECLSPEC_NORETURN void WINAPI GC_ExitThread(DWORD /* dwExitCode */);
#    else
struct _SECURITY_ATTRIBUTES;
GC_API void *__stdcall GC_CreateThread(struct _SECURITY_ATTRIBUTES *,
                                       GC_WIN32_SIZE_T,
                                       unsigned long(__stdcall *)(void *),
                                       void *, unsigned long, unsigned long *);
GC_API DECLSPEC_NORETURN void __stdcall GC_ExitThread(unsigned long);
#    endif

#    if !defined(_WIN32_WCE) && !defined(__CEGCC__)
GC_API GC_uintptr_t GC_CALL GC_beginthreadex(void * /* security */,
                                             unsigned /* stack_size */,
                                             unsigned(__stdcall *)(void *),
                                             void * /* arglist */,
                                             unsigned /* initflag */,
                                             unsigned * /* thrdaddr */);

/* Note: _endthreadex() is not currently marked as no-return in   */
/* VC++ and MinGW headers, so we don't mark it neither.           */
GC_API void GC_CALL GC_endthreadex(unsigned /* retval */);
#    endif /* !_WIN32_WCE */

#  endif /* !GC_NO_THREAD_DECLS */

#  ifdef GC_WINMAIN_REDIRECT
/* The collector provides the real WinMain(), which starts a new    */
/* thread to call GC_WinMain() after initializing the GC.           */
#    define WinMain GC_WinMain
#  endif

/* For compatibility only. */
#  define GC_use_DllMain GC_use_threads_discovery

#  ifndef GC_NO_THREAD_REDIRECTS
#    define CreateThread GC_CreateThread
#    define ExitThread GC_ExitThread
#    undef _beginthreadex
#    define _beginthreadex GC_beginthreadex
#    undef _endthreadex
#    define _endthreadex GC_endthreadex
/* #define _beginthread { > "Please use _beginthreadex instead of _beginthread"
 * < } */
#  endif /* !GC_NO_THREAD_REDIRECTS */

#endif /* GC_WIN32_THREADS */

/* The setter and the getter for switching "unmap as much as possible"  */
/* mode on(1) and off(0).  Has no effect unless unmapping is turned on. */
/* Has no effect on implicitly-initiated garbage collections.  Initial  */
/* value is controlled by GC_FORCE_UNMAP_ON_GCOLLECT.  The setter and   */
/* the getter are unsynchronized.                                       */
GC_API void GC_CALL GC_set_force_unmap_on_gcollect(int);
GC_API int GC_CALL GC_get_force_unmap_on_gcollect(void);

/* Fully portable code should call GC_INIT() from the main program      */
/* before making any other GC_ calls.  On most platforms this is a      */
/* no-op and the collector self-initializes.  But a number of           */
/* platforms make that too hard.                                        */
/* A GC_INIT call is required if the collector is built with            */
/* THREAD_LOCAL_ALLOC defined and the initial allocation call is not    */
/* to GC_malloc() or GC_malloc_atomic().                                */

#if defined(__CYGWIN32__) || defined(__CYGWIN__)
/* Similarly gnu-win32 DLLs need explicit initialization from the     */
/* main program, as does AIX.                                         */
#  ifdef __x86_64__
/* Cygwin/x64 does not add leading underscore to symbols anymore.   */
extern int __data_start__[], __data_end__[];
extern int __bss_start__[], __bss_end__[];
#    define GC_DATASTART                                         \
      (GC_ADDR_LT((char *)__data_start__, (char *)__bss_start__) \
           ? (void *)__data_start__                              \
           : (void *)__bss_start__)
#    define GC_DATAEND                                       \
      (GC_ADDR_LT((char *)__bss_end__, (char *)__data_end__) \
           ? (void *)__data_end__                            \
           : (void *)__bss_end__)
#  else
extern int _data_start__[], _data_end__[], _bss_start__[], _bss_end__[];
#    define GC_DATASTART                                       \
      (GC_ADDR_LT((char *)_data_start__, (char *)_bss_start__) \
           ? (void *)_data_start__                             \
           : (void *)_bss_start__)
#    define GC_DATAEND                                     \
      (GC_ADDR_LT((char *)_bss_end__, (char *)_data_end__) \
           ? (void *)_data_end__                           \
           : (void *)_bss_end__)
#  endif /* !__x86_64__ */
/* This is required at least if GC is in a DLL.  And doesn't hurt.    */
#  define GC_INIT_CONF_ROOTS                \
    GC_add_roots(GC_DATASTART, GC_DATAEND); \
    GC_gcollect() /* For blacklisting. */
#elif defined(_AIX)
extern int _data[], _end[];
#  define GC_DATASTART ((void *)_data)
#  define GC_DATAEND ((void *)_end)
#  define GC_INIT_CONF_ROOTS GC_add_roots(GC_DATASTART, GC_DATAEND)
#elif (defined(HOST_ANDROID) || defined(__ANDROID__)) \
    && defined(IGNORE_DYNAMIC_LOADING)
/* This is ugly but seems the only way to register data roots of the  */
/* client shared library if the GC dynamic loading support is off.    */
#  pragma weak __dso_handle
extern int __dso_handle[];
GC_API void *GC_CALL GC_find_limit(void * /* start */, int /* up */);
#  define GC_INIT_CONF_ROOTS                                           \
    (void)(__dso_handle != 0                                           \
               ? (GC_add_roots(__dso_handle,                           \
                               GC_find_limit(__dso_handle, 1 /*up*/)), \
                  0)                                                   \
               : 0)
#else
#  define GC_INIT_CONF_ROOTS /* empty */
#endif

#ifdef GC_DONT_EXPAND
/* Set GC_dont_expand to true at start-up.    */
#  define GC_INIT_CONF_DONT_EXPAND GC_set_dont_expand(1)
#else
#  define GC_INIT_CONF_DONT_EXPAND /* empty */
#endif

#ifdef GC_FORCE_UNMAP_ON_GCOLLECT
/* Turn on "unmap as much as possible on explicit GC" mode at start-up */
#  define GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT \
    GC_set_force_unmap_on_gcollect(1)
#else
#  define GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT /* empty */
#endif

#ifdef GC_DONT_GC
/* This is for debugging only (useful if environment variables are    */
/* unsupported); cannot call GC_disable() as goes before the GC       */
/* initialization.                                                    */
#  define GC_INIT_CONF_MAX_RETRIES (void)(GC_dont_gc = 1)
#elif defined(GC_MAX_RETRIES) && !defined(CPPCHECK)
/* Set GC_max_retries to the desired value at start-up */
#  define GC_INIT_CONF_MAX_RETRIES GC_set_max_retries(GC_MAX_RETRIES)
#else
#  define GC_INIT_CONF_MAX_RETRIES /* empty */
#endif

#if defined(GC_ALLOCD_BYTES_PER_FINALIZER) && !defined(CPPCHECK)
/* Set GC_allocd_bytes_per_finalizer to the desired value at start-up. */
#  define GC_INIT_CONF_ALLOCD_BYTES_PER_FINALIZER \
    GC_set_allocd_bytes_per_finalizer(GC_ALLOCD_BYTES_PER_FINALIZER)
#else
#  define GC_INIT_CONF_ALLOCD_BYTES_PER_FINALIZER /* empty */
#endif

#if defined(GC_FREE_SPACE_DIVISOR) && !defined(CPPCHECK)
/* Set GC_free_space_divisor to the desired value at start-up */
#  define GC_INIT_CONF_FREE_SPACE_DIVISOR \
    GC_set_free_space_divisor(GC_FREE_SPACE_DIVISOR)
#else
#  define GC_INIT_CONF_FREE_SPACE_DIVISOR /* empty */
#endif

#if defined(GC_FULL_FREQ) && !defined(CPPCHECK)
/* Set GC_full_freq to the desired value at start-up */
#  define GC_INIT_CONF_FULL_FREQ GC_set_full_freq(GC_FULL_FREQ)
#else
#  define GC_INIT_CONF_FULL_FREQ /* empty */
#endif

#if defined(GC_TIME_LIMIT) && !defined(CPPCHECK)
/* Set GC_time_limit (in ms) to the desired value at start-up. */
#  define GC_INIT_CONF_TIME_LIMIT GC_set_time_limit(GC_TIME_LIMIT)
#else
#  define GC_INIT_CONF_TIME_LIMIT /* empty */
#endif

#if defined(GC_MARKERS) && defined(GC_THREADS) && !defined(CPPCHECK)
/* Set the number of marker threads (including the initiating */
/* one) to the desired value at start-up.                     */
#  define GC_INIT_CONF_MARKERS GC_set_markers_count(GC_MARKERS)
#else
#  define GC_INIT_CONF_MARKERS /* empty */
#endif

#if defined(GC_SIG_SUSPEND) && defined(GC_THREADS) && !defined(CPPCHECK)
#  define GC_INIT_CONF_SUSPEND_SIGNAL GC_set_suspend_signal(GC_SIG_SUSPEND)
#else
#  define GC_INIT_CONF_SUSPEND_SIGNAL /* empty */
#endif

#if defined(GC_SIG_THR_RESTART) && defined(GC_THREADS) && !defined(CPPCHECK)
#  define GC_INIT_CONF_THR_RESTART_SIGNAL \
    GC_set_thr_restart_signal(GC_SIG_THR_RESTART)
#else
#  define GC_INIT_CONF_THR_RESTART_SIGNAL /* empty */
#endif

#if defined(GC_MAXIMUM_HEAP_SIZE) && !defined(CPPCHECK)
/* Limit the heap size to the desired value (useful for debugging).   */
/* The limit could be overridden either at the program start-up by    */
/* the similar environment variable or anytime later by the           */
/* corresponding API function call.                                   */
#  define GC_INIT_CONF_MAXIMUM_HEAP_SIZE \
    GC_set_max_heap_size(GC_MAXIMUM_HEAP_SIZE)
#else
#  define GC_INIT_CONF_MAXIMUM_HEAP_SIZE /* empty */
#endif

#ifdef GC_IGNORE_WARN
/* Turn off all warnings at start-up (after the collector initialization). */
#  define GC_INIT_CONF_IGNORE_WARN GC_set_warn_proc(GC_ignore_warn_proc)
#else
#  define GC_INIT_CONF_IGNORE_WARN /* empty */
#endif

#if defined(GC_INITIAL_HEAP_SIZE) && !defined(CPPCHECK)
/* Set heap size to the desired value at start-up */
#  define GC_INIT_CONF_INITIAL_HEAP_SIZE                                  \
    {                                                                     \
      size_t heap_size = GC_get_heap_size();                              \
      if (heap_size < (size_t)(GC_INITIAL_HEAP_SIZE))                     \
        (void)GC_expand_hp(((size_t)(GC_INITIAL_HEAP_SIZE)) - heap_size); \
    }
#else
#  define GC_INIT_CONF_INITIAL_HEAP_SIZE /* empty */
#endif

/* Portable clients should call this at the program start-up.  More     */
/* over, some platforms require this call to be done strictly from the  */
/* primordial thread.  Multiple invocations are harmless.               */
#define GC_INIT()                                    \
  {                                                  \
    GC_INIT_CONF_DONT_EXPAND; /* pre-init */         \
    GC_INIT_CONF_FORCE_UNMAP_ON_GCOLLECT;            \
    GC_INIT_CONF_MAX_RETRIES;                        \
    GC_INIT_CONF_ALLOCD_BYTES_PER_FINALIZER;         \
    GC_INIT_CONF_FREE_SPACE_DIVISOR;                 \
    GC_INIT_CONF_FULL_FREQ;                          \
    GC_INIT_CONF_TIME_LIMIT;                         \
    GC_INIT_CONF_MARKERS;                            \
    GC_INIT_CONF_SUSPEND_SIGNAL;                     \
    GC_INIT_CONF_THR_RESTART_SIGNAL;                 \
    GC_INIT_CONF_MAXIMUM_HEAP_SIZE;                  \
    GC_init();          /* real GC initialization */ \
    GC_INIT_CONF_ROOTS; /* post-init */              \
    GC_INIT_CONF_IGNORE_WARN;                        \
    GC_INIT_CONF_INITIAL_HEAP_SIZE;                  \
  }

/* win32s may not free all resources on process exit.                   */
/* This explicitly deallocates the heap.  Defined only for Windows.     */
GC_API void GC_CALL GC_win32_free_heap(void);

#if defined(__SYMBIAN32__)
GC_API void GC_CALL GC_init_global_static_roots(void);
#endif

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* GC_H */
